diff --git a/src/Makefile.am b/src/Makefile.am
index bdf8a7dcba..c9b5ab4c4a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -335,7 +335,6 @@ BITCOIN_CORE_H = \
   wallet/fees.h \
   wallet/ismine.h \
   wallet/load.h \
-  wallet/psbtwallet.h \
   wallet/rpcwallet.h \
   wallet/salvage.h \
   wallet/scriptpubkeyman.h \
@@ -499,7 +498,6 @@ libbitcoin_wallet_a_SOURCES = \
   wallet/db.cpp \
   wallet/fees.cpp \
   wallet/load.cpp \
-  wallet/psbtwallet.cpp \
   wallet/rpcdump.cpp \
   wallet/rpcwallet.cpp \
   wallet/scriptpubkeyman.cpp \
diff --git a/src/coinjoin/client.cpp b/src/coinjoin/client.cpp
index c7777d08cf..aaa2ebb571 100644
--- a/src/coinjoin/client.cpp
+++ b/src/coinjoin/client.cpp
@@ -620,7 +620,7 @@ bool CCoinJoinClientSession::SignFinalTransaction(const CTxMemPool& mempool, con
 
             LogPrint(BCLog::COINJOIN, "CCoinJoinClientSession::%s -- Signing my input %i\n", __func__, nMyInputIndex);
             // TODO we're using amount=0 here but we should use the correct amount. This works because Dash ignores the amount while signing/verifying (only used in Bitcoin/Segwit)
-            if (!SignSignature(*mixingWallet.GetSigningProvider(prevPubKey), prevPubKey, finalMutableTransaction, nMyInputIndex, 0, int(SIGHASH_ALL | SIGHASH_ANYONECANPAY))) { // changes scriptSig
+            if (!SignSignature(*mixingWallet.GetSolvingProvider(prevPubKey), prevPubKey, finalMutableTransaction, nMyInputIndex, 0, int(SIGHASH_ALL | SIGHASH_ANYONECANPAY))) { // changes scriptSig
                 LogPrint(BCLog::COINJOIN, "CCoinJoinClientSession::%s -- Unable to sign my own transaction!\n", __func__);
                 // not sure what to do here, it will time out...?
             }
@@ -1541,7 +1541,7 @@ bool CCoinJoinClientSession::CreateCollateralTransaction(CMutableTransaction& tx
         txCollateral.vout.emplace_back(0, CScript() << OP_RETURN);
     }
 
-    if (!SignSignature(*mixingWallet.GetSigningProvider(txout.scriptPubKey), txout.scriptPubKey, txCollateral, 0, txout.nValue, SIGHASH_ALL)) {
+    if (!SignSignature(*mixingWallet.GetSolvingProvider(txout.scriptPubKey), txout.scriptPubKey, txCollateral, 0, txout.nValue, SIGHASH_ALL)) {
         strReason = "Unable to sign collateral transaction!";
         return false;
     }
diff --git a/src/interfaces/wallet.cpp b/src/interfaces/wallet.cpp
index ae29fb5cb3..815e32946c 100644
--- a/src/interfaces/wallet.cpp
+++ b/src/interfaces/wallet.cpp
@@ -22,7 +22,6 @@
 #include <wallet/fees.h>
 #include <wallet/ismine.h>
 #include <wallet/load.h>
-#include <wallet/psbtwallet.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
 
@@ -192,19 +191,15 @@ public:
     }
     bool getPubKey(const CScript& script, const CKeyID& address, CPubKey& pub_key) override
     {
-        std::unique_ptr<SigningProvider> provider = m_wallet->GetSigningProvider(script);
+        std::unique_ptr<SigningProvider> provider = m_wallet->GetSolvingProvider(script);
         if (provider) {
             return provider->GetPubKey(address, pub_key);
         }
         return false;
     }
-    bool getPrivKey(const CScript& script, const CKeyID& address, CKey& key) override
+    SigningResult signMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) override
     {
-        std::unique_ptr<SigningProvider> provider = m_wallet->GetSigningProvider(script);
-        if (provider) {
-            return provider->GetKey(address, key);
-        }
-        return false;
+        return m_wallet->SignMessage(message, pkhash, str_sig);
     }
     bool isSpendable(const CScript& script) override { return m_wallet->IsMine(script) & ISMINE_SPENDABLE; }
     bool isSpendable(const CTxDestination& dest) override { return m_wallet->IsMine(dest) & ISMINE_SPENDABLE; }
@@ -404,9 +399,9 @@ public:
         bool& complete,
         int sighash_type = 1 /* SIGHASH_ALL */,
         bool sign = true,
-        bool bip32derivs = false) override
+        bool bip32derivs = false) const override
     {
-        return FillPSBT(m_wallet.get(), psbtx, complete, sighash_type, sign, bip32derivs);
+        return m_wallet->FillPSBT(psbtx, complete, sighash_type, sign, bip32derivs);
     }
     WalletBalances getBalances() override
     {
diff --git a/src/interfaces/wallet.h b/src/interfaces/wallet.h
index 3f68b9777b..fba448f54c 100644
--- a/src/interfaces/wallet.h
+++ b/src/interfaces/wallet.h
@@ -12,7 +12,7 @@
 #include <script/standard.h>           // For CTxDestination
 #include <support/allocators/secure.h> // For SecureString
 #include <ui_interface.h>              // For ChangeType
-#include <util/system.h>
+#include <util/message.h>
 
 #include <functional>
 #include <map>
@@ -117,8 +117,8 @@ public:
     //! Get public key.
     virtual bool getPubKey(const CScript& script, const CKeyID& address, CPubKey& pub_key) = 0;
 
-    //! Get private key.
-    virtual bool getPrivKey(const CScript& script, const CKeyID& address, CKey& key) = 0;
+    //! Sign message
+    virtual SigningResult signMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) = 0;
 
     //! Return whether wallet has private key.
     virtual bool isSpendable(const CScript& script) = 0;
@@ -223,7 +223,7 @@ public:
         bool& complete,
         int sighash_type = 1 /* SIGHASH_ALL */,
         bool sign = true,
-        bool bip32derivs = false) = 0;
+        bool bip32derivs = false) const = 0;
 
     //! Get balances.
     virtual WalletBalances getBalances() = 0;
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index 6e07593fb4..889fa610d8 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -26,7 +26,6 @@
 #include <ui_interface.h>
 #include <wallet/coincontrol.h>
 #include <wallet/fees.h>
-#include <wallet/psbtwallet.h>
 #include <wallet/wallet.h>
 
 #include <QFontMetrics>
diff --git a/src/qt/signverifymessagedialog.cpp b/src/qt/signverifymessagedialog.cpp
index 9bd2b20cd9..3ad4b84a21 100644
--- a/src/qt/signverifymessagedialog.cpp
+++ b/src/qt/signverifymessagedialog.cpp
@@ -161,20 +161,27 @@ void SignVerifyMessageDialog::on_signMessageButton_SM_clicked()
         return;
     }
 
-    CKey key;
-    if (!model->wallet().getPrivKey(GetScriptForDestination(destination), CKeyID(*pkhash), key))
-    {
-        ui->statusLabel_SM->setStyleSheet(GUIUtil::getThemedStyleQString(GUIUtil::ThemedStyle::TS_ERROR));
-        ui->statusLabel_SM->setText(tr("Private key for the entered address is not available."));
-        return;
-    }
-
     const std::string& message = ui->messageIn_SM->document()->toPlainText().toStdString();
     std::string signature;
+    SigningResult res = model->wallet().signMessage(message, *pkhash, signature);
 
-    if (!MessageSign(key, message, signature)) {
+    QString error;
+    switch (res) {
+        case SigningResult::OK:
+            error = tr("No error");
+            break;
+        case SigningResult::PRIVATE_KEY_NOT_AVAILABLE:
+            error = tr("Private key for the entered address is not available.");
+            break;
+        case SigningResult::SIGNING_FAILED:
+            error = tr("Message signing failed.");
+            break;
+        // no default case, so the compiler can warn about missing cases
+    }
+
+    if (res != SigningResult::OK) {
         ui->statusLabel_SM->setStyleSheet(GUIUtil::getThemedStyleQString(GUIUtil::ThemedStyle::TS_ERROR));
-        ui->statusLabel_SM->setText(QString("<nobr>") + tr("Message signing failed.") + QString("</nobr>"));
+        ui->statusLabel_SM->setText(QString("<nobr>") + error + QString("</nobr>"));
         return;
     }
 
diff --git a/src/rpc/rawtransaction_util.cpp b/src/rpc/rawtransaction_util.cpp
index c1f69009c5..9f22f0555a 100644
--- a/src/rpc/rawtransaction_util.cpp
+++ b/src/rpc/rawtransaction_util.cpp
@@ -228,6 +228,10 @@ void SignTransactionResultToJSON(CMutableTransaction& mtx, bool complete, const
     // Make errors UniValue
     UniValue vErrors(UniValue::VARR);
     for (const auto& err_pair : input_errors) {
+        if (err_pair.second == "Missing amount") {
+            // This particular error needs to be an exception for some reason
+            throw JSONRPCError(RPC_TYPE_ERROR, strprintf("Missing amount for %s", coins.at(mtx.vin.at(err_pair.first).prevout).out.ToString()));
+        }
         TxInErrorToJSON(mtx.vin.at(err_pair.first), vErrors, err_pair.second);
     }
 
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index 62b745ffb3..6cbbdfcd8b 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -425,6 +425,9 @@ bool SignTransaction(CMutableTransaction& mtx, const SigningProvider* keystore,
             } else {
                 input_errors[i] = ScriptErrorString(serror);
             }
+        } else {
+            // If this input succeeds, make sure there is no error set for it
+            input_errors.erase(i);
         }
     }
     return input_errors.empty();
diff --git a/src/util/message.cpp b/src/util/message.cpp
index 9008279cc9..ac2a1f8306 100644
--- a/src/util/message.cpp
+++ b/src/util/message.cpp
@@ -76,3 +76,17 @@ uint256 MessageHash(const std::string& message)
 
     return hasher.GetHash();
 }
+
+std::string SigningResultString(const SigningResult res)
+{
+    switch (res) {
+        case SigningResult::OK:
+            return "No error";
+        case SigningResult::PRIVATE_KEY_NOT_AVAILABLE:
+            return "Private key not available";
+        case SigningResult::SIGNING_FAILED:
+            return "Sign failed";
+        // no default case, so the compiler can warn about missing cases
+    }
+    assert(false);
+}
diff --git a/src/util/message.h b/src/util/message.h
index 01fd14ce2d..b31c5f5761 100644
--- a/src/util/message.h
+++ b/src/util/message.h
@@ -39,6 +39,12 @@ enum class MessageVerificationResult {
     OK
 };
 
+enum class SigningResult {
+    OK, //!< No error
+    PRIVATE_KEY_NOT_AVAILABLE,
+    SIGNING_FAILED,
+};
+
 /** Verify a signed message.
  * @param[in] address Signer's bitcoin address, it must refer to a public key.
  * @param[in] signature The signature in base64 format.
@@ -65,4 +71,6 @@ bool MessageSign(
  */
 uint256 MessageHash(const std::string& message);
 
+std::string SigningResultString(const SigningResult res);
+
 #endif // BITCOIN_UTIL_MESSAGE_H
diff --git a/src/wallet/psbtwallet.cpp b/src/wallet/psbtwallet.cpp
deleted file mode 100644
index 9aacc0d398..0000000000
--- a/src/wallet/psbtwallet.cpp
+++ /dev/null
@@ -1,76 +0,0 @@
-// Copyright (c) 2009-2018 The Bitcoin Core developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#include <wallet/psbtwallet.h>
-
-TransactionError FillPSBT(const CWallet* pwallet, PartiallySignedTransaction& psbtx, bool& complete, int sighash_type, bool sign, bool bip32derivs)
-{
-    LOCK(pwallet->cs_wallet);
-    // Get all of the previous transactions
-    complete = true;
-    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
-        const CTxIn& txin = psbtx.tx->vin[i];
-        PSBTInput& input = psbtx.inputs.at(i);
-
-        if (PSBTInputSigned(input)) {
-            continue;
-        }
-
-        // Verify input looks sane. This will check that we have at most one uxto.
-        if (!input.IsSane()) {
-            return TransactionError::INVALID_PSBT;
-        }
-
-        // If we have no utxo, grab it from the wallet.
-        if (!input.non_witness_utxo) {
-            const uint256& txhash = txin.prevout.hash;
-            const auto it = pwallet->mapWallet.find(txhash);
-            if (it != pwallet->mapWallet.end()) {
-                const CWalletTx& wtx = it->second;
-                // We only need the non_witness_utxo, which is a superset of the witness_utxo.
-                //   The signing code will switch to the smaller witness_utxo if this is ok.
-                input.non_witness_utxo = wtx.tx;
-            }
-        }
-
-        // Get the Sighash type
-        if (sign && input.sighash_type > 0 && input.sighash_type != sighash_type) {
-            return TransactionError::SIGHASH_MISMATCH;
-        }
-
-        // Get the scriptPubKey to know which SigningProvider to use
-        CScript script;
-        if (input.non_witness_utxo) {
-            if (txin.prevout.n >= input.non_witness_utxo->vout.size()) {
-                return TransactionError::MISSING_INPUTS;
-            }
-            script = input.non_witness_utxo->vout[txin.prevout.n].scriptPubKey;
-        } else {
-            // There's no UTXO so we can just skip this now
-            complete = false;
-            continue;
-        }
-        SignatureData sigdata;
-        input.FillSignatureData(sigdata);
-        std::unique_ptr<SigningProvider> provider = pwallet->GetSigningProvider(script, sigdata);
-        if (!provider) {
-            complete = false;
-            continue;
-        }
-
-        complete &= SignPSBTInput(HidingSigningProvider(provider.get(), !sign, !bip32derivs), psbtx, i, sighash_type);
-    }
-
-    // Fill in the bip32 keypaths and redeemscripts for the outputs so that hardware wallets can identify change
-    for (unsigned int i = 0; i < psbtx.tx->vout.size(); ++i) {
-        const CTxOut& out = psbtx.tx->vout.at(i);
-        std::unique_ptr<SigningProvider> provider = pwallet->GetSigningProvider(out.scriptPubKey);
-        if (provider) {
-            UpdatePSBTOutput(HidingSigningProvider(provider.get(), true, !bip32derivs), psbtx, i);
-        }
-    }
-
-    return TransactionError::OK;
-}
-
diff --git a/src/wallet/psbtwallet.h b/src/wallet/psbtwallet.h
deleted file mode 100644
index 17b40c0c1b..0000000000
--- a/src/wallet/psbtwallet.h
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright (c) 2009-2019 The Bitcoin Core developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#ifndef BITCOIN_WALLET_PSBTWALLET_H
-#define BITCOIN_WALLET_PSBTWALLET_H
-
-#include <psbt.h>
-#include <wallet/wallet.h>
-
-/**
- * Fills out a PSBT with information from the wallet. Fills in UTXOs if we have
- * them. Tries to sign if sign=true. Sets `complete` if the PSBT is now complete
- * (i.e. has all required signatures or signature-parts, and is ready to
- * finalize.) Sets `error` and returns false if something goes wrong.
- *
- * @param[in]  pwallet pointer to a wallet
- * @param[in]  psbtx PartiallySignedTransaction to fill in
- * @param[out] complete indicates whether the PSBT is now complete
- * @param[in]  sighash_type the sighash type to use when signing (if PSBT does not specify)
- * @param[in]  sign whether to sign or not
- * @param[in]  bip32derivs whether to fill in bip32 derivation information if available
- * return error
- */
-[[nodiscard]] TransactionError FillPSBT(const CWallet* pwallet,
-              PartiallySignedTransaction& psbtx,
-              bool& complete,
-              int sighash_type = 1 /* SIGHASH_ALL */,
-              bool sign = true,
-              bool bip32derivs = true);
-
-#endif // BITCOIN_WALLET_PSBTWALLET_H
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 8e88120710..1c92cac730 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -29,7 +29,6 @@
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/context.h>
-#include <wallet/psbtwallet.h>
 #include <wallet/load.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/scriptpubkeyman.h>
@@ -602,21 +601,12 @@ static UniValue signmessage(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to key");
     }
 
-    CScript script_pub_key = GetScriptForDestination(*pkhash);
-    std::unique_ptr<SigningProvider> provider = pwallet->GetSigningProvider(script_pub_key);
-    if (!provider) {
-        throw JSONRPCError(RPC_WALLET_ERROR, "Private key not available");
-    }
-
-    CKey key;
-    if (!provider->GetKey(CKeyID(*pkhash), key)) {
-        throw JSONRPCError(RPC_WALLET_ERROR, "Private key not available");
-    }
-
     std::string signature;
-
-    if (!MessageSign(key, strMessage, signature)) {
-        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Sign failed");
+    SigningResult err = pwallet->SignMessage(strMessage, *pkhash, signature);
+    if (err == SigningResult::SIGNING_FAILED) {
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, SigningResultString(err));
+    } else if (err != SigningResult::OK){
+        throw JSONRPCError(RPC_WALLET_ERROR, SigningResultString(err));
     }
 
     return signature;
@@ -3160,7 +3150,7 @@ static UniValue listunspent(const JSONRPCRequest& request)
                 entry.pushKV("label", i->second.name);
             }
 
-            std::unique_ptr<SigningProvider> provider = pwallet->GetSigningProvider(scriptPubKey);
+            std::unique_ptr<SigningProvider> provider = pwallet->GetSolvingProvider(scriptPubKey);
             if (provider) {
                 if (scriptPubKey.IsPayToScriptHash()) {
                     const CScriptID& hash = CScriptID(std::get<ScriptHash>(address));
@@ -3178,7 +3168,7 @@ static UniValue listunspent(const JSONRPCRequest& request)
         entry.pushKV("spendable", out.fSpendable);
         entry.pushKV("solvable", out.fSolvable);
         if (out.fSolvable) {
-            std::unique_ptr<SigningProvider> provider = pwallet->GetSigningProvider(scriptPubKey);
+            std::unique_ptr<SigningProvider> provider = pwallet->GetSolvingProvider(scriptPubKey);
             if (provider) {
                 auto descriptor = InferDescriptor(scriptPubKey, *provider);
                 entry.pushKV("desc", descriptor->ToString());
@@ -3459,23 +3449,15 @@ UniValue signrawtransactionwithwallet(const JSONRPCRequest& request)
     // Parse the prevtxs array
     ParsePrevouts(request.params[1], nullptr, coins);
 
-    std::set<std::shared_ptr<SigningProvider>> providers;
-    for (const std::pair<COutPoint, Coin> coin_pair : coins) {
-        std::unique_ptr<SigningProvider> provider = pwallet->GetSigningProvider(coin_pair.second.out.scriptPubKey);
-        if (provider) {
-            providers.insert(std::move(provider));
-        }
-    }
-    if (providers.size() == 0) {
-        // When there are no available providers, use a dummy SigningProvider so we can check if the tx is complete
-        providers.insert(std::make_shared<SigningProvider>());
-    }
+    int nHashType = ParseSighashString(request.params[2]);
 
+    // Script verification errors
+    std::map<int, std::string> input_errors;
+
+    bool complete = pwallet->SignTransaction(mtx, coins, nHashType, input_errors);
     UniValue result(UniValue::VOBJ);
-    for (std::shared_ptr<SigningProvider> provider : providers) {
-        SignTransaction(mtx, provider.get(), coins, request.params[2], result);
-    }
-     return result;
+    SignTransactionResultToJSON(mtx, complete, coins, input_errors, result);
+    return result;
 }
 
 static UniValue rescanblockchain(const JSONRPCRequest& request)
@@ -3621,7 +3603,7 @@ static UniValue DescribeWalletAddress(const CWallet* const pwallet, const CTxDes
     CScript script = GetScriptForDestination(dest);
     std::unique_ptr<SigningProvider> provider = nullptr;
     if (pwallet) {
-        provider = pwallet->GetSigningProvider(script);
+        provider = pwallet->GetSolvingProvider(script);
     }
     ret.pushKVs(detail);
     ret.pushKVs(std::visit(DescribeWalletAddressVisitor(provider.get()), dest));
@@ -3714,7 +3696,7 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
     CScript scriptPubKey = GetScriptForDestination(dest);
     ret.pushKV("scriptPubKey", HexStr(scriptPubKey));
 
-    std::unique_ptr<SigningProvider> provider = pwallet->GetSigningProvider(scriptPubKey);
+    std::unique_ptr<SigningProvider> provider = pwallet->GetSolvingProvider(scriptPubKey);
 
     isminetype mine = pwallet->IsMine(dest);
     ret.pushKV("ismine", bool(mine & ISMINE_SPENDABLE));
@@ -3938,7 +3920,7 @@ UniValue walletprocesspsbt(const JSONRPCRequest& request)
     bool sign = request.params[1].isNull() ? true : request.params[1].get_bool();
     bool bip32derivs = request.params[3].isNull() ? true : request.params[3].get_bool();
     bool complete = true;
-    const TransactionError err = FillPSBT(pwallet, psbtx, complete, nHashType, sign, bip32derivs);
+    const TransactionError err = pwallet->FillPSBT(psbtx, complete, nHashType, sign, bip32derivs);
     if (err != TransactionError::OK) {
         throw JSONRPCTransactionError(err);
     }
@@ -4049,7 +4031,7 @@ UniValue walletcreatefundedpsbt(const JSONRPCRequest& request)
     // Fill transaction with out data but don't sign
     bool bip32derivs = request.params[4].isNull() ? true : request.params[4].get_bool();
     bool complete = true;
-    const TransactionError err = FillPSBT(pwallet, psbtx, complete, 1, false, bip32derivs);
+    const TransactionError err = pwallet->FillPSBT(psbtx, complete, 1, false, bip32derivs);
     if (err != TransactionError::OK) {
         throw JSONRPCTransactionError(err);
     }
diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index 4ada17b8ab..b947842532 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -6,6 +6,7 @@
 #include <chainparams.h>
 #include <logging.h>
 #include <script/descriptor.h>
+#include <script/sign.h>
 #include <ui_interface.h>
 #include <util/bip32.h>
 #include <util/strencodings.h>
@@ -649,7 +650,7 @@ int64_t LegacyScriptPubKeyMan::GetTimeFirstKey() const
     return nTimeFirstKey;
 }
 
-std::unique_ptr<SigningProvider> LegacyScriptPubKeyMan::GetSigningProvider(const CScript& script) const
+std::unique_ptr<SigningProvider> LegacyScriptPubKeyMan::GetSolvingProvider(const CScript& script) const
 {
     return std::make_unique<LegacySigningProvider>(*this);
 }
@@ -677,6 +678,67 @@ bool LegacyScriptPubKeyMan::CanProvide(const CScript& script, SignatureData& sig
     }
 }
 
+bool LegacyScriptPubKeyMan::SignTransaction(CMutableTransaction& tx, const std::map<COutPoint, Coin>& coins, int sighash, std::map<int, std::string>& input_errors) const
+{
+    return ::SignTransaction(tx, this, coins, sighash, input_errors);
+}
+
+SigningResult LegacyScriptPubKeyMan::SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const
+{
+    CKeyID key_id(pkhash);
+    CKey key;
+    if (!GetKey(key_id, key)) {
+        return SigningResult::PRIVATE_KEY_NOT_AVAILABLE;
+    }
+
+    if (MessageSign(key, message, str_sig)) {
+        return SigningResult::OK;
+    }
+    return SigningResult::SIGNING_FAILED;
+}
+
+TransactionError LegacyScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbtx, int sighash_type, bool sign, bool bip32derivs) const
+{
+    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
+        const CTxIn& txin = psbtx.tx->vin[i];
+        PSBTInput& input = psbtx.inputs.at(i);
+
+        if (PSBTInputSigned(input)) {
+            continue;
+        }
+
+        // Verify input looks sane. This will check that we have at most one uxto.
+        if (!input.IsSane()) {
+            return TransactionError::INVALID_PSBT;
+        }
+
+        // Get the Sighash type
+        if (sign && input.sighash_type > 0 && input.sighash_type != sighash_type) {
+            return TransactionError::SIGHASH_MISMATCH;
+        }
+
+        // Check non_witness_utxo has specified prevout
+        if (input.non_witness_utxo) {
+            if (txin.prevout.n >= input.non_witness_utxo->vout.size()) {
+                return TransactionError::MISSING_INPUTS;
+            }
+        } else {
+            // There's no UTXO so we can just skip this now
+            continue;
+        }
+        SignatureData sigdata;
+        input.FillSignatureData(sigdata);
+        SignPSBTInput(HidingSigningProvider(this, !sign, !bip32derivs), psbtx, i, sighash_type);
+    }
+
+    // Fill in the bip32 keypaths and redeemscripts for the outputs so that hardware wallets can identify change
+    for (unsigned int i = 0; i < psbtx.tx->vout.size(); ++i) {
+        UpdatePSBTOutput(HidingSigningProvider(this, true, !bip32derivs), psbtx, i);
+    }
+
+    return TransactionError::OK;
+}
+
 const CKeyMetadata* LegacyScriptPubKeyMan::GetMetadata(const CTxDestination& dest) const
 {
     LOCK(cs_KeyStore);
diff --git a/src/wallet/scriptpubkeyman.h b/src/wallet/scriptpubkeyman.h
index 906fd927f3..8a7694298c 100644
--- a/src/wallet/scriptpubkeyman.h
+++ b/src/wallet/scriptpubkeyman.h
@@ -5,8 +5,11 @@
 #ifndef BITCOIN_WALLET_SCRIPTPUBKEYMAN_H
 #define BITCOIN_WALLET_SCRIPTPUBKEYMAN_H
 
+#include <psbt.h>
 #include <script/signingprovider.h>
 #include <script/standard.h>
+#include <util/error.h>
+#include <util/message.h>
 #include <util/time.h>
 #include <wallet/crypter.h>
 #include <wallet/ismine.h>
@@ -190,13 +193,20 @@ public:
 
     virtual const CKeyMetadata* GetMetadata(const CTxDestination& dest) const { return nullptr; }
 
-    virtual std::unique_ptr<SigningProvider> GetSigningProvider(const CScript& script) const { return nullptr; }
+    virtual std::unique_ptr<SigningProvider> GetSolvingProvider(const CScript& script) const { return nullptr; }
 
-    /** Whether this ScriptPubKeyMan can provide a SigningProvider (via GetSigningProvider) that, combined with
-      * sigdata, can produce a valid signature.
+    /** Whether this ScriptPubKeyMan can provide a SigningProvider (via GetSolvingProvider) that, combined with
+      * sigdata, can produce solving data.
       */
     virtual bool CanProvide(const CScript& script, SignatureData& sigdata) { return false; }
 
+    /** Creates new signatures and adds them to the transaction. Returns whether all inputs were signed */
+    virtual bool SignTransaction(CMutableTransaction& tx, const std::map<COutPoint, Coin>& coins, int sighash, std::map<int, std::string>& input_errors) const { return false; }
+    /** Sign a message with the given script */
+    virtual SigningResult SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const { return SigningResult::SIGNING_FAILED; };
+    /** Adds script and derivation path information to a PSBT, and optionally signs it. */
+    virtual TransactionError FillPSBT(PartiallySignedTransaction& psbt, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false) const { return TransactionError::INVALID_PSBT; }
+
     virtual uint256 GetID() const { return uint256(); }
 
     /** Prepends the wallet name in logging output to ease debugging in multi-wallet use cases */
@@ -332,10 +342,14 @@ public:
 
     bool CanGetAddresses(bool internal = false) const override;
 
-    std::unique_ptr<SigningProvider> GetSigningProvider(const CScript& script) const override;
+    std::unique_ptr<SigningProvider> GetSolvingProvider(const CScript& script) const override;
 
     bool CanProvide(const CScript& script, SignatureData& sigdata) override;
 
+    bool SignTransaction(CMutableTransaction& tx, const std::map<COutPoint, Coin>& coins, int sighash, std::map<int, std::string>& input_errors) const override;
+    SigningResult SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const override;
+    TransactionError FillPSBT(PartiallySignedTransaction& psbt, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false) const override;
+
     uint256 GetID() const override;
 
     // Map from Key ID to key metadata.
@@ -466,7 +480,7 @@ public:
     std::set<CKeyID> GetKeys() const override;
 };
 
-/** Wraps a LegacyScriptPubKeyMan so that it can be returned in a new unique_ptr */
+/** Wraps a LegacyScriptPubKeyMan so that it can be returned in a new unique_ptr. Does not provide privkeys */
 class LegacySigningProvider : public SigningProvider
 {
 private:
@@ -477,8 +491,8 @@ public:
     bool GetCScript(const CScriptID &scriptid, CScript& script) const override { return m_spk_man.GetCScript(scriptid, script); }
     bool HaveCScript(const CScriptID &scriptid) const override { return m_spk_man.HaveCScript(scriptid); }
     bool GetPubKey(const CKeyID &address, CPubKey& pubkey) const override { return m_spk_man.GetPubKey(address, pubkey); }
-    bool GetKey(const CKeyID &address, CKey& key) const override { return m_spk_man.GetKey(address, key); }
-    bool HaveKey(const CKeyID &address) const override { return m_spk_man.HaveKey(address); }
+    bool GetKey(const CKeyID &address, CKey& key) const override { return false; }
+    bool HaveKey(const CKeyID &address) const override { return false; }
     bool GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const override { return m_spk_man.GetKeyOrigin(keyid, info); }
 };
 
diff --git a/src/wallet/test/psbt_wallet_tests.cpp b/src/wallet/test/psbt_wallet_tests.cpp
index 15e0a8b380..274cefd2ac 100644
--- a/src/wallet/test/psbt_wallet_tests.cpp
+++ b/src/wallet/test/psbt_wallet_tests.cpp
@@ -5,7 +5,6 @@
 #include <key_io.h>
 #include <util/bip32.h>
 #include <util/strencodings.h>
-#include <wallet/psbtwallet.h>
 #include <wallet/wallet.h>
 
 #include <boost/test/unit_test.hpp>
@@ -60,7 +59,7 @@ BOOST_AUTO_TEST_CASE(psbt_updater_test)
 
     // Fill transaction with our data
     bool complete = true;
-    BOOST_REQUIRE_EQUAL(TransactionError::OK, FillPSBT(&m_wallet, psbtx, complete, SIGHASH_ALL, false, true));
+    BOOST_REQUIRE_EQUAL(TransactionError::OK, m_wallet.FillPSBT(psbtx, complete, SIGHASH_ALL, false, true));
 
     // Get the final tx
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
@@ -74,9 +73,7 @@ BOOST_AUTO_TEST_CASE(psbt_updater_test)
 
     // Try to sign the mutated input
     SignatureData sigdata;
-    psbtx.inputs[0].FillSignatureData(sigdata);
-    const std::unique_ptr<SigningProvider> provider = m_wallet.GetSigningProvider(ws1, sigdata);
-    BOOST_CHECK(!SignPSBTInput(*provider, psbtx, 0, SIGHASH_ALL));
+    BOOST_CHECK(spk_man->FillPSBT(psbtx, SIGHASH_ALL, true, true) != TransactionError::OK);
 }
 
 BOOST_AUTO_TEST_CASE(parse_hd_keypath)
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 4db163d312..8c22bb824a 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1674,7 +1674,7 @@ bool CWallet::DummySignInput(CTxIn &tx_in, const CTxOut &txout, bool use_max_sig
     const CScript& scriptPubKey = txout.scriptPubKey;
     SignatureData sigdata;
 
-    std::unique_ptr<SigningProvider> provider = GetSigningProvider(scriptPubKey);
+    std::unique_ptr<SigningProvider> provider = GetSolvingProvider(scriptPubKey);
     if (!provider) {
         // We don't know about this scriptpbuKey;
         return false;
@@ -2595,7 +2595,7 @@ void CWallet::AvailableCoins(std::vector<COutput> &vCoins, bool fOnlySafe, const
                 continue;
             }
 
-            std::unique_ptr<SigningProvider> provider = GetSigningProvider(pcoin->tx->vout[i].scriptPubKey);
+            std::unique_ptr<SigningProvider> provider = GetSolvingProvider(pcoin->tx->vout[i].scriptPubKey);
 
             bool solvable = provider ? IsSolvable(*provider, pcoin->tx->vout[i].scriptPubKey) : false;
             bool spendable = ((mine & ISMINE_SPENDABLE) != ISMINE_NO) || (((mine & ISMINE_WATCH_ONLY) != ISMINE_NO) && (coinControl && coinControl->fAllowWatchOnly && solvable));
@@ -2862,6 +2862,175 @@ bool CWallet::SelectCoins(const std::vector<COutput>& vAvailableCoins, const CAm
     return res;
 }
 
+// KNST KNST TODO
+/// !!!!!!!! check with psbtwallet
+bool CWallet::SignTransaction(CMutableTransaction& tx) const
+{
+    AssertLockHeld(cs_wallet);
+
+    // Build coins map
+    std::map<COutPoint, Coin> coins;
+    for (auto& input : tx.vin) {
+        std::map<uint256, CWalletTx>::const_iterator mi = mapWallet.find(input.prevout.hash);
+        if(mi == mapWallet.end() || input.prevout.n >= mi->second.tx->vout.size()) {
+            return false;
+        }
+        const CWalletTx& wtx = mi->second;
+        coins[input.prevout] = Coin(wtx.tx->vout[input.prevout.n], wtx.m_confirm.block_height, wtx.IsCoinBase());
+    }
+    std::map<int, std::string> input_errors;
+    return SignTransaction(tx, coins, SIGHASH_ALL, input_errors);
+}
+
+bool CWallet::SignTransaction(CMutableTransaction& tx, const std::map<COutPoint, Coin>& coins, int sighash, std::map<int, std::string>& input_errors) const
+{
+    // Sign the tx with ScriptPubKeyMans
+    // Because each ScriptPubKeyMan can sign more than one input, we need to keep track of each ScriptPubKeyMan that has signed this transaction.
+    // Each iteration, we may sign more txins than the txin that is specified in that iteration.
+    // We assume that each input is signed by only one ScriptPubKeyMan.
+    std::set<uint256> visited_spk_mans;
+    for (unsigned int i = 0; i < tx.vin.size(); i++) {
+        // Get the prevout
+        CTxIn& txin = tx.vin[i];
+        auto coin = coins.find(txin.prevout);
+        if (coin == coins.end() || coin->second.IsSpent()) {
+            input_errors[i] = "Input not found or already spent";
+            continue;
+        }
+
+        // Check if this input is complete
+        SignatureData sigdata = DataFromTransaction(tx, i, coin->second.out);
+        if (sigdata.complete) {
+            continue;
+        }
+
+        // Input needs to be signed, find the right ScriptPubKeyMan
+        std::set<ScriptPubKeyMan*> spk_mans = GetScriptPubKeyMans(coin->second.out.scriptPubKey, sigdata);
+        if (spk_mans.size() == 0) {
+            input_errors[i] = "Unable to sign input, missing keys";
+            continue;
+        }
+
+        for (auto& spk_man : spk_mans) {
+            // If we've already been signed by this spk_man, skip it
+            if (visited_spk_mans.count(spk_man->GetID()) > 0) {
+                continue;
+            }
+
+            // Sign the tx.
+            // spk_man->SignTransaction will return true if the transaction is complete,
+            // so we can exit early and return true if that happens.
+            if (spk_man->SignTransaction(tx, coins, sighash, input_errors)) {
+                return true;
+            }
+
+            // Add this spk_man to visited_spk_mans so we can skip it later
+            visited_spk_mans.insert(spk_man->GetID());
+        }
+    }
+    return false;
+}
+
+TransactionError CWallet::FillPSBT(PartiallySignedTransaction& psbtx, bool& complete, int sighash_type, bool sign, bool bip32derivs) const
+{
+    LOCK(cs_wallet);
+    // Get all of the previous transactions
+    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
+        const CTxIn& txin = psbtx.tx->vin[i];
+        PSBTInput& input = psbtx.inputs.at(i);
+
+        if (PSBTInputSigned(input)) {
+            continue;
+        }
+
+        // Verify input looks sane. This will check that we have at most one uxto, witness or non-witness.
+        if (!input.IsSane()) {
+            return TransactionError::INVALID_PSBT;
+        }
+
+        // If we have no utxo, grab it from the wallet.
+        if (!input.non_witness_utxo) {
+            const uint256& txhash = txin.prevout.hash;
+            const auto it = mapWallet.find(txhash);
+            if (it != mapWallet.end()) {
+                const CWalletTx& wtx = it->second;
+                // We only need the non_witness_utxo, which is a superset of the witness_utxo.
+                //   The signing code will switch to the smaller witness_utxo if this is ok.
+                input.non_witness_utxo = wtx.tx;
+            }
+        }
+    }
+
+    // Fill in information from ScriptPubKeyMans
+    // Because each ScriptPubKeyMan may be able to fill more than one input, we need to keep track of each ScriptPubKeyMan that has filled this psbt.
+    // Each iteration, we may fill more inputs than the input that is specified in that iteration.
+    // We assume that each input is filled by only one ScriptPubKeyMan
+    std::set<uint256> visited_spk_mans;
+    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
+        const CTxIn& txin = psbtx.tx->vin[i];
+        PSBTInput& input = psbtx.inputs.at(i);
+
+        if (PSBTInputSigned(input)) {
+            continue;
+        }
+
+        // Get the scriptPubKey to know which SigningProvider to use
+        CScript script;
+        if (input.non_witness_utxo) {
+            if (txin.prevout.n >= input.non_witness_utxo->vout.size()) {
+                return TransactionError::MISSING_INPUTS;
+            }
+            script = input.non_witness_utxo->vout[txin.prevout.n].scriptPubKey;
+        } else {
+            // There's no UTXO so we can just skip this now
+            complete = false;
+            continue;
+        }
+        SignatureData sigdata;
+        input.FillSignatureData(sigdata);
+        std::set<ScriptPubKeyMan*> spk_mans = GetScriptPubKeyMans(script, sigdata);
+        if (spk_mans.size() == 0) {
+            continue;
+        }
+
+        for (auto& spk_man : spk_mans) {
+            // If we've already been signed by this spk_man, skip it
+            if (visited_spk_mans.count(spk_man->GetID()) > 0) {
+                continue;
+            }
+
+            // Fill in the information from the spk_man
+            TransactionError res = spk_man->FillPSBT(psbtx, sighash_type, sign, bip32derivs);
+            if (res != TransactionError::OK) {
+                return res;
+            }
+
+            // Add this spk_man to visited_spk_mans so we can skip it later
+            visited_spk_mans.insert(spk_man->GetID());
+        }
+    }
+
+    // Complete if every input is now signed
+    complete = true;
+    for (const auto& input : psbtx.inputs) {
+        complete &= PSBTInputSigned(input);
+    }
+
+    return TransactionError::OK;
+}
+
+SigningResult CWallet::SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const
+{
+    SignatureData sigdata;
+    CScript script_pub_key = GetScriptForDestination(pkhash);
+    for (const auto& spk_man_pair : m_spk_managers) {
+        if (spk_man_pair.second->CanProvide(script_pub_key, sigdata)) {
+            return spk_man_pair.second->SignMessage(message, pkhash, str_sig);
+        }
+    }
+    return SigningResult::PRIVATE_KEY_NOT_AVAILABLE;
+}
+
 bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, bilingual_str& error, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, CCoinControl coinControl)
 {
     std::vector<CRecipient> vecSend;
@@ -3533,25 +3702,9 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CTransac
         // Make sure change position was updated one way or another
         assert(nChangePosInOut != std::numeric_limits<int>::max());
 
-        if (sign)
-        {
-            int nIn = 0;
-            for(const auto& coin : vecCoins)
-            {
-                const CScript& scriptPubKey = coin.txout.scriptPubKey;
-                SignatureData sigdata;
-
-                std::unique_ptr<SigningProvider> provider = GetSigningProvider(scriptPubKey);
-                if (!provider || !ProduceSignature(*provider, MutableTransactionSignatureCreator(&txNew, nIn, coin.txout.nValue, SIGHASH_ALL), scriptPubKey, sigdata))
-                {
-                    error = _("Signing transaction failed");
-                    return false;
-                } else {
-                    UpdateInput(txNew.vin.at(nIn), sigdata);
-                }
-
-                nIn++;
-            }
+        if (sign && !SignTransaction(txNew)) {
+            error = _("Signing transaction failed");
+            return false;
         }
 
         // Return the constructed transaction data.
@@ -5090,6 +5243,17 @@ ScriptPubKeyMan* CWallet::GetScriptPubKeyMan(bool internal) const
     return spk_manager;
 }
 
+std::set<ScriptPubKeyMan*> CWallet::GetScriptPubKeyMans(const CScript& script, SignatureData& sigdata) const
+{
+    std::set<ScriptPubKeyMan*> spk_mans;
+    for (const auto& spk_man_pair : m_spk_managers) {
+        if (spk_man_pair.second->CanProvide(script, sigdata)) {
+            spk_mans.insert(spk_man_pair.second.get());
+        }
+    }
+    return spk_mans;
+}
+
 ScriptPubKeyMan* CWallet::GetScriptPubKeyMan(const CScript& script) const
 {
     SignatureData sigdata;
@@ -5109,17 +5273,17 @@ ScriptPubKeyMan* CWallet::GetScriptPubKeyMan(const uint256& id) const
     return nullptr;
 }
 
-std::unique_ptr<SigningProvider> CWallet::GetSigningProvider(const CScript& script) const
+std::unique_ptr<SigningProvider> CWallet::GetSolvingProvider(const CScript& script) const
 {
     SignatureData sigdata;
-    return GetSigningProvider(script, sigdata);
+    return GetSolvingProvider(script, sigdata);
 }
 
-std::unique_ptr<SigningProvider> CWallet::GetSigningProvider(const CScript& script, SignatureData& sigdata) const
+std::unique_ptr<SigningProvider> CWallet::GetSolvingProvider(const CScript& script, SignatureData& sigdata) const
 {
     for (const auto& spk_man_pair : m_spk_managers) {
         if (spk_man_pair.second->CanProvide(script, sigdata)) {
-            return spk_man_pair.second->GetSigningProvider(script);
+            return spk_man_pair.second->GetSolvingProvider(script);
         }
     }
     return nullptr;
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index ad30e146c2..2a8e153232 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -11,9 +11,11 @@
 #include <interfaces/chain.h>
 #include <interfaces/handler.h>
 #include <policy/feerate.h>
+#include <psbt.h>
 #include <saltedhasher.h>
 #include <tinyformat.h>
 #include <ui_interface.h>
+#include <util/message.h>
 #include <util/string.h>
 #include <util/system.h>
 #include <util/strencodings.h>
@@ -1009,7 +1011,30 @@ public:
      * calling CreateTransaction();
      */
     bool FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, bilingual_str& error, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, CCoinControl);
-    bool SignTransaction(CMutableTransaction& tx) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    // Fetch the inputs and sign with SIGHASH_ALL.
+    bool SignTransaction(CMutableTransaction& tx) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    // Sign the tx given the input coins and sighash.
+    bool SignTransaction(CMutableTransaction& tx, const std::map<COutPoint, Coin>& coins, int sighash, std::map<int, std::string>& input_errors) const;
+    SigningResult SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const;
+
+    /**
+     * Fills out a PSBT with information from the wallet. Fills in UTXOs if we have
+     * them. Tries to sign if sign=true. Sets `complete` if the PSBT is now complete
+     * (i.e. has all required signatures or signature-parts, and is ready to
+     * finalize.) Sets `error` and returns false if something goes wrong.
+     *
+     * @param[in]  psbtx PartiallySignedTransaction to fill in
+     * @param[out] complete indicates whether the PSBT is now complete
+     * @param[in]  sighash_type the sighash type to use when signing (if PSBT does not specify)
+     * @param[in]  sign whether to sign or not
+     * @param[in]  bip32derivs whether to fill in bip32 derivation information if available
+     * return error
+     */
+    [[nodiscard]] TransactionError FillPSBT(PartiallySignedTransaction& psbtx,
+                  bool& complete,
+                  int sighash_type = 1 /* SIGHASH_ALL */,
+                  bool sign = true,
+                  bool bip32derivs = true) const;
 
     /**
      * Create a new transaction paying the recipients with a set of coins
@@ -1273,9 +1298,12 @@ public:
     //! Get the ScriptPubKeyMan by id
     ScriptPubKeyMan* GetScriptPubKeyMan(const uint256& id) const;
 
+    //! Get all of the ScriptPubKeyMans for a script given additional information in sigdata (populated by e.g. a psbt)
+    std::set<ScriptPubKeyMan*> GetScriptPubKeyMans(const CScript& script, SignatureData& sigdata) const;
+
     //! Get the SigningProvider for a script
-    std::unique_ptr<SigningProvider> GetSigningProvider(const CScript& script) const;
-    std::unique_ptr<SigningProvider> GetSigningProvider(const CScript& script, SignatureData& sigdata) const;
+    std::unique_ptr<SigningProvider> GetSolvingProvider(const CScript& script) const;
+    std::unique_ptr<SigningProvider> GetSolvingProvider(const CScript& script, SignatureData& sigdata) const;
 
     //! Get the LegacyScriptPubKeyMan which is used for all types, internal, and external.
     LegacyScriptPubKeyMan* GetLegacyScriptPubKeyMan() const;