diff --git a/src/ui/windows/send_tab.cpp b/src/ui/windows/send_tab.cpp
index ca0ff2a..d045039 100644
--- a/src/ui/windows/send_tab.cpp
+++ b/src/ui/windows/send_tab.cpp
@@ -130,6 +130,15 @@ static void ClearFormWithUndo() {
 
 static double GetAvailableBalance(App* app) {
     const auto& state = app->getWalletState();
+    // Resolve the balance by the source ADDRESS STRING (the value actually debited on send),
+    // not a stored list index. The index desyncs from s_from_address after an address-list
+    // refresh, and is left at -1 when the source is chosen from another tab ("Send from this
+    // address") — which previously made the sufficiency check see 0 and block a valid send.
+    if (s_from_address[0] != '\0') {
+        for (const auto& a : state.addresses) {
+            if (a.address == s_from_address) return a.balance;
+        }
+    }
     if (s_selected_from_idx >= 0 && s_selected_from_idx < static_cast<int>(state.addresses.size())) {
         return state.addresses[s_selected_from_idx].balance;
     }