diff --git a/cw_bitcoin/lib/electrum.dart b/cw_bitcoin/lib/electrum.dart
index 44aa096c4..b3bc6e843 100644
--- a/cw_bitcoin/lib/electrum.dart
+++ b/cw_bitcoin/lib/electrum.dart
@@ -579,14 +579,29 @@ class ElectrumClient {
         return [];
       });
 
+  // Floor at 0 so unavailable/-1 estimates never become negative rates;
+  // cap at 2000 sat/vB per CW-1597.
+  static const int _maxFeeRate = 2000;
+
+  static int _sanitizeFeeRate(double feeRate) {
+    final rate = (stringDoubleToBitcoinAmount(feeRate.toString()) / 1000).round();
+    if (rate < 0) {
+      return 0;
+    }
+    if (rate > _maxFeeRate) {
+      return _maxFeeRate;
+    }
+    return rate;
+  }
+
   Future<List<int>> feeRates({BasedUtxoNetwork? network}) async {
     try {
-      final topDoubleString = await estimatefee(p: 1);
-      final middleDoubleString = await estimatefee(p: 5);
-      final bottomDoubleString = await estimatefee(p: 10);
-      final top = (stringDoubleToBitcoinAmount(topDoubleString.toString()) / 1000).round();
-      final middle = (stringDoubleToBitcoinAmount(middleDoubleString.toString()) / 1000).round();
-      final bottom = (stringDoubleToBitcoinAmount(bottomDoubleString.toString()) / 1000).round();
+      final topDouble = await estimatefee(p: 1);
+      final middleDouble = await estimatefee(p: 5);
+      final bottomDouble = await estimatefee(p: 10);
+      final top = _sanitizeFeeRate(topDouble);
+      final middle = _sanitizeFeeRate(middleDouble);
+      final bottom = _sanitizeFeeRate(bottomDouble);
 
       return [bottom, middle, top];
     } catch (_) {
diff --git a/cw_bitcoin/lib/electrum_wallet.dart b/cw_bitcoin/lib/electrum_wallet.dart
index 5d3af65f5..857317a90 100644
--- a/cw_bitcoin/lib/electrum_wallet.dart
+++ b/cw_bitcoin/lib/electrum_wallet.dart
@@ -750,6 +750,9 @@ abstract class ElectrumWalletBase
     }
   }
 
+  static bool _isValidFeeRates(List<int> feeRates) =>
+      feeRates.length == 3 && feeRates.every((rate) => rate > 0);
+
   @action
   Future<void> updateFeeRates() async {
     if (await checkIfMempoolAPIIsEnabled() && type == WalletType.bitcoin) {
@@ -776,7 +779,7 @@ abstract class ElectrumWalletBase
     }
 
     final feeRates = await electrumClient.feeRates(network: network);
-    if (feeRates != [0, 0, 0]) {
+    if (_isValidFeeRates(feeRates)) {
       _feeRates = feeRates;
     } else if (isTestnet) {
       _feeRates = [1, 1, 1];
@@ -1024,7 +1027,7 @@ abstract class ElectrumWalletBase
       vinOutpoints: utxoDetails.vinOutpoints,
     );
 
-    if (fee == 0) {
+    if (fee <= 0) {
       throw BitcoinTransactionNoFeeException();
     }
 
@@ -1205,7 +1208,7 @@ abstract class ElectrumWalletBase
       ));
     }
 
-    if (fee == 0) {
+    if (fee <= 0) {
       throw BitcoinTransactionNoFeeException();
     }
 
@@ -2513,16 +2516,16 @@ abstract class ElectrumWalletBase
     Map<String, ElectrumTransactionInfo> historiesWithDetails,
     BitcoinAddressType type,
   ) async {
-
     final addressesByType =
-    walletAddresses.allAddresses.where((addr) => addr.type == type).toList();
+        walletAddresses.allAddresses.where((addr) => addr.type == type).toList();
 
     final receiveStandard = getAddressBranchByType(hidden: false, legacy: false, type: type);
-    final changeStandard = getAddressBranchByType(hidden: true,  legacy: false, type: type);
+    final changeStandard = getAddressBranchByType(hidden: true, legacy: false, type: type);
     final receiveLegacy = getAddressBranchByType(hidden: false, legacy: true, type: type);
-    final changeLegacy = getAddressBranchByType(hidden: true,  legacy: true, type: type);
+    final changeLegacy = getAddressBranchByType(hidden: true, legacy: true, type: type);
 
-    walletAddresses.hiddenAddresses.addAll([...changeStandard, ...changeLegacy].map((e) => e.address));
+    walletAddresses.hiddenAddresses
+        .addAll([...changeStandard, ...changeLegacy].map((e) => e.address));
     await walletAddresses.saveAddressesInBox();
     await Future.wait(addressesByType.map((addressRecord) async {
       final history = await _fetchAddressHistory(addressRecord, await getCurrentChainTip());
@@ -2637,13 +2640,13 @@ abstract class ElectrumWalletBase
 
   Future<void> fetchTransactionsForAddressTypeBatch(
       Map<String, ElectrumTransactionInfo> historiesWithDetails, BitcoinAddressType type) async {
-
     final receiveStandard = getAddressBranchByType(hidden: false, legacy: false, type: type);
-    final changeStandard = getAddressBranchByType(hidden: true,  legacy: false, type: type);
+    final changeStandard = getAddressBranchByType(hidden: true, legacy: false, type: type);
     final receiveLegacy = getAddressBranchByType(hidden: false, legacy: true, type: type);
-    final changeLegacy = getAddressBranchByType(hidden: true,  legacy: true, type: type);
+    final changeLegacy = getAddressBranchByType(hidden: true, legacy: true, type: type);
 
-    walletAddresses.hiddenAddresses.addAll([...changeStandard, ...changeLegacy].map((e) => e.address));
+    walletAddresses.hiddenAddresses
+        .addAll([...changeStandard, ...changeLegacy].map((e) => e.address));
     await walletAddresses.saveAddressesInBox();
 
     await fetchTransactionsForAddressesBranchBatch(
@@ -2665,7 +2668,7 @@ abstract class ElectrumWalletBase
     await fetchTransactionsForAddressesBranchBatch(
       historiesWithDetails,
       type,
-       receiveLegacy,
+      receiveLegacy,
       isHidden: false,
       isLegacyDerivation: true,
     );
@@ -2749,10 +2752,13 @@ abstract class ElectrumWalletBase
     }
   }
 
-  List<BitcoinAddressRecord> getAddressBranchByType({required bool hidden, required bool legacy, required BitcoinAddressType
-  type}) => walletAddresses.allAddresses.where((addr) => addr.type == type && addr.isHidden == hidden && addr.isLegacyDerivation == legacy)
-        .toList()
-      ..sort((a, b) => a.index.compareTo(b.index));
+  List<BitcoinAddressRecord> getAddressBranchByType(
+          {required bool hidden, required bool legacy, required BitcoinAddressType type}) =>
+      walletAddresses.allAddresses
+          .where((addr) =>
+              addr.type == type && addr.isHidden == hidden && addr.isLegacyDerivation == legacy)
+          .toList()
+        ..sort((a, b) => a.index.compareTo(b.index));
 
   int _highestUsedIndex(List<BitcoinAddressRecord> addresses) {
     for (int i = addresses.length - 1; i >= 0; i--) {