diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 421656152cb..a71a69a02f0 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -639,16 +639,37 @@ static RPCHelpMan combinerawtransaction()
 {
 
     UniValue txs = request.params[0].get_array();
+
+    // Can't merge < 2 items
+    if (txs.size() < 2) {
+        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Missing transactions");
+    }
+
     std::vector<CMutableTransaction> txVariants(txs.size());
 
-    for (unsigned int idx = 0; idx < txs.size(); idx++) {
+    for (unsigned int idx{0}; idx < txs.size(); ++idx) {
         if (!DecodeHexTx(txVariants[idx], txs[idx].get_str())) {
             throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed for tx %d. Make sure the tx has at least one input.", idx));
         }
     }
 
-    if (txVariants.empty()) {
-        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Missing transactions");
+    { // Test Tx relation for mergeability. This involves converting each tx to PSBT format (stripping sigscripts/witnesses) and ensuring txid is consistent.
+        std::vector<CMutableTransaction> txVariantsCopy(txVariants);
+        Txid txid{};
+        for (unsigned int k{0}; k < txVariantsCopy.size(); ++k) {
+            // Remove all scriptSigs and scriptWitnesses from inputs
+            for (CTxIn& input : txVariantsCopy[k].vin) {
+                input.scriptSig.clear();
+                input.scriptWitness.SetNull();
+            }
+            if (k == 0) {
+                txid = txVariantsCopy[k].GetHash();
+            } else {
+                if (txid != txVariantsCopy[k].GetHash()) {
+                    throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Transaction %d not compatible (different transactions)", k));
+                }
+            }
+        }
     }
 
     // mergedTx will end up with all the signatures; it
@@ -678,7 +699,7 @@ static RPCHelpMan combinerawtransaction()
     // transaction to avoid rehashing.
     const CTransaction txConst(mergedTx);
     // Sign what we can:
-    for (unsigned int i = 0; i < mergedTx.vin.size(); i++) {
+    for (unsigned int i{0}; i < mergedTx.vin.size(); ++i) {
         CTxIn& txin = mergedTx.vin[i];
         const Coin& coin = view.AccessCoin(txin.prevout);
         if (coin.IsSpent()) {
diff --git a/test/functional/rpc_createmultisig.py b/test/functional/rpc_createmultisig.py
index 0692a1203df..09868eccc4e 100755
--- a/test/functional/rpc_createmultisig.py
+++ b/test/functional/rpc_createmultisig.py
@@ -199,8 +199,18 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         assert_equal(rawtx3["complete"], False)
         assert_raises_rpc_error(-22, "TX decode failed", node2.combinerawtransaction, [rawtx2['hex'], rawtx3['hex'] + "00"])
         assert_raises_rpc_error(-22, "Missing transactions", node2.combinerawtransaction, [])
+        assert_raises_rpc_error(-22, "Missing transactions", node2.combinerawtransaction, [rawtx2['hex']])
         combined_rawtx = node2.combinerawtransaction([rawtx2["hex"], rawtx3["hex"]])
 
+        # transactions are not related
+        UNRELATED_TXID = "1d1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000"
+        unrelatedTx = self.nodes[2].createrawtransaction(inputs=[{'txid': UNRELATED_TXID, 'vout': 9}], outputs=[{out_addr: 99}])
+        assert_raises_rpc_error(-8, "Transaction 1 not compatible (different transactions)", self.nodes[0].combinerawtransaction, [rawtx2['hex'], unrelatedTx])
+
+        # Accept duplicate transactions in combinerawtransaction
+        dupeMergedTx = self.nodes[0].combinerawtransaction([rawtx2['hex'], rawtx2['hex']])
+        assert_equal(rawtx2['hex'], dupeMergedTx)
+
         tx = node0.sendrawtransaction(combined_rawtx, 0)
         blk = self.generate(node0, 1)[0]
         assert tx in node0.getblock(blk)["tx"]