diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index 71bd3c0e9..8af9d7712 100755
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -274,6 +274,8 @@ public:
     // Default transaction version.
     static const int32_t CURRENT_VERSION=2;
 
+    static const int32_t MAX_FLO_DATA_SIZE=1040;
+
     // Changing the default transaction version requires a two step process: first
     // adapting relay policy by bumping MAX_STANDARD_VERSION, and then later date
     // bumping the default CURRENT_VERSION at which point both CURRENT_VERSION and
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index bbae830f4..b3235bbba 100755
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -19,6 +19,7 @@
 #include "base58.h"
 #include "chainparams.h"
 #include "wallet/coincontrol.h"
+#include "primitives/transaction.h" // FloData size limits
 #include "validation.h" // mempool and minRelayTxFee
 #include "ui_interface.h"
 #include "txmempool.h"
@@ -133,6 +134,8 @@ SendCoinsDialog::SendCoinsDialog(const PlatformStyle *_platformStyle, QWidget *p
     ui->customFee->setValue(settings.value("nTransactionFee").toLongLong());
     ui->checkBoxMinimumFee->setChecked(settings.value("fPayOnlyMinFee").toBool());
     minimizeFeeSection(settings.value("fFeeSectionMinimized").toBool());
+
+    ui->floData->setMaxLength(CTransaction::MAX_FLO_DATA_SIZE-5); // room for "text:" prefix
 }
 
 void SendCoinsDialog::setClientModel(ClientModel *_clientModel)
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 1fb91e343..021454bce 100755
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -353,6 +353,10 @@ UniValue createrawtransaction(const JSONRPCRequest& request)
         rawTx.strFloData = request.params[4].get_str();
     }
 
+    if (rawTx.strFloData.length() > CTransaction::MAX_FLO_DATA_SIZE) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, Flo Data too large");
+    }
+
     for (unsigned int idx = 0; idx < inputs.size(); idx++) {
         const UniValue& input = inputs[idx];
         const UniValue& o = input.get_obj();
@@ -612,6 +616,9 @@ UniValue combinerawtransaction(const JSONRPCRequest& request)
     // starts as a clone of the rawtx:
     CMutableTransaction mergedTx(txVariants[0]);
     mergedTx.strFloData = strFloData;
+    if (mergedTx.strFloData.length() > CTransaction::MAX_FLO_DATA_SIZE) {
+        throw JSONRPCError(RPC_VERIFY_ERROR, "Flo Data too large");
+    }
 
     // Fetch previous transactions (inputs):
     CCoinsView viewDummy;
@@ -935,6 +942,11 @@ UniValue sendrawtransaction(const JSONRPCRequest& request)
     CMutableTransaction mtx;
     if (!DecodeHexTx(mtx, request.params[0].get_str()))
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
+
+    if (mtx.strFloData.length() > CTransaction::MAX_FLO_DATA_SIZE) {
+        throw JSONRPCError(RPC_TRANSACTION_ERROR, "Flo Data too large");
+    }
+
     CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
     const uint256& hashTx = tx->GetHash();
 
diff --git a/src/validation.cpp b/src/validation.cpp
index 0a3bc343d..345d6f2cb 100755
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -461,14 +461,8 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
         return state.DoS(0, false, REJECT_NONSTANDARD, "no-witness-yet", true);
     }
 
-    if (tx.nVersion >= 2) {
-        int maxCommentLen = 528;
-        if (witnessEnabled) {
-            maxCommentLen = 1040;
-        }
-        if (tx.strFloData.length() > maxCommentLen) {
-            return state.DoS(0, false, REJECT_INVALID, "flo-data-too-large");
-        }
+    if (tx.strFloData.length() > CTransaction::MAX_FLO_DATA_SIZE) {
+        return state.DoS(0, false, REJECT_INVALID, "flo-data-too-large");
     }
 
     // Rather not work on nonstandard transactions (unless -testnet/-regtest)
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 15965afb6..15f2e9709 100755
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -379,6 +379,10 @@ static void SendMoney(CWallet * const pwallet, const CTxDestination &address, CA
 {
     CAmount curBalance = pwallet->GetBalance();
 
+    if (strFloData.length() > CTransaction::MAX_FLO_DATA_SIZE) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Flo data too long");
+    }
+
     // Check amount
     if (nValue <= 0)
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid amount");
@@ -1065,6 +1069,10 @@ UniValue sendmany(const JSONRPCRequest& request)
     if (totalAmount > nBalance)
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, "Account has insufficient funds");
 
+    if (strFloData.length() > CTransaction::MAX_FLO_DATA_SIZE) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Flo data too long");
+    }
+
     // Send
     CReserveKey keyChange(pwallet);
     CAmount nFeeRequired = 0;