diff --git a/arma/server/addons/bank/functions/fnc_initBankStore.sqf b/arma/server/addons/bank/functions/fnc_initBankStore.sqf
index 48d8896..bc46888 100644
--- a/arma/server/addons/bank/functions/fnc_initBankStore.sqf
+++ b/arma/server/addons/bank/functions/fnc_initBankStore.sqf
@@ -328,6 +328,11 @@ GVAR(BankBaseStore) = compileFinal createHashMapFromArray [
             GVAR(BankMessenger) call ["sendAlert", [_uid, "error", _result select [7]]];
             createHashMap
         };
+        if !(_result in ["true", "false"]) exitWith {
+            ["ERROR", format ["Bank exists check for %1 returned unexpected response: %2", _uid, _result]] call EFUNC(common,log);
+            GVAR(BankMessenger) call ["sendAlert", [_uid, "error", "Bank backend returned an unexpected existence response."]];
+            createHashMap
+        };
 
         private _finalAccount = createHashMap;
         private _wasCreated = false;
diff --git a/arma/server/extension/src/bank.rs b/arma/server/extension/src/bank.rs
index 2cf62b7..48b9b16 100644
--- a/arma/server/extension/src/bank.rs
+++ b/arma/server/extension/src/bank.rs
@@ -548,6 +548,8 @@ pub fn update_bank(call_context: CallContext, key: String, json_update: String)
 /// Checks if an bank exists in the database.
 ///
 /// Returns "true" if the bank exists, "false" otherwise.
+/// Backend failures are returned as errors so callers do not confuse a failed
+/// lookup with a missing account and create duplicate/default records.
 pub fn bank_exists(call_context: CallContext, key: String) -> String {
     log(
         "bank",
@@ -561,12 +563,9 @@ pub fn bank_exists(call_context: CallContext, key: String) -> String {
             uid
         }
         None => {
-            log(
-                "bank",
-                "WARN",
-                &format!("Failed to resolve UID for key: {}", key),
-            );
-            return "false".to_string();
+            let error_msg = format!("Error: Failed to resolve UID for key: {}", key);
+            log("bank", "ERROR", &error_msg);
+            return error_msg;
         }
     };
 
@@ -580,12 +579,13 @@ pub fn bank_exists(call_context: CallContext, key: String) -> String {
             exists.to_string()
         }
         Err(e) => {
+            let error_msg = format!("Error: {}", e);
             log(
                 "bank",
                 "ERROR",
                 &format!("Failed to check if bank '{}' exists: {}", resolved_uid, e),
             );
-            "false".to_string()
+            error_msg
         }
     }
 }