diff --git a/TalerWallet1/Views/Settings/Bank/BankEditView.swift b/TalerWallet1/Views/Settings/Bank/BankEditView.swift
index c77b9f01..43c055b1 100755
--- a/TalerWallet1/Views/Settings/Bank/BankEditView.swift
+++ b/TalerWallet1/Views/Settings/Bank/BankEditView.swift
@@ -59,6 +59,16 @@ struct BankEditView: View {
 //        }
 //    }
 
+    /// An x-taler-bank target is BANK-HOST/ACCOUNT (RFC 8905). wallet-core rejects
+    /// anything with fewer than two components as
+    /// "payto URI is malformed (COMPONENTS_LENGTH)", which reached the user as
+    /// "Internal core error" with the raw JSON. Check it here instead.
+    private var xTalerValid: Bool {
+        let parts = xTaler.split(separator: "/", omittingEmptySubsequences: false)
+        return parts.count >= 2
+            && parts.allSatisfy { !$0.isEmpty && !$0.contains(where: { $0.isWhitespace }) }
+    }
+
     @ViewBuilder func barButton() -> some View {
         let isNew = accountID == nil
         let titleStr = isNew ? String(localized: "Add", comment: "button title: Add bank account")
@@ -66,7 +76,7 @@ struct BankEditView: View {
         let a11yStr = isNew ? String(localized: "Add bank account", comment: "a11y")
                             : String(localized: "Update bank account", comment: "a11y")
         let notValid: Bool = paytoType == .iban ? (iban.isEmpty || !ibanValid)
-                                                : xTaler.isEmpty
+                                                : !xTalerValid
         DoneButton(titleStr: titleStr, accessibilityLabelStr: titleStr) {
             Task {
                 if await updateAccount() {
@@ -105,7 +115,7 @@ struct BankEditView: View {
         let isIBAN = paytoType == .iban
         if !accountHolder.isEmpty && !accountLabel.isEmpty {
             if isIBAN ? !iban.isEmpty
-                      : !xTaler.isEmpty {
+                      : xTalerValid {
                 // Build the payto URI with URLComponents so each component is escaped as a
                 // component. The previous code percent-encoded the ALREADY-ASSEMBLED string
                 // with .urlQueryAllowed, which leaves "?", "&" and "=" untouched — an
@@ -266,12 +276,21 @@ struct BankEditView: View {
                         .foregroundColor(WalletColors().fieldForeground)     // text color
                         .background(WalletColors().fieldBackground)
                         .textFieldStyle(.roundedBorder)
-                        .padding(.bottom)
+                        .autocapitalization(.none)
+                        .disableAutocorrection(true)
+                        .padding(.bottom, xTaler.isEmpty || xTalerValid ? nil : 0)
                         .onChange(of: xTaler) { newValue in
                             if userTyped {
                                 unchanged = false
                             }
                         }
+                    if !xTaler.isEmpty && !xTalerValid {
+                        Text("Enter the account as BANK-HOST/ACCOUNT, for example bank.example.com/alice",
+                             comment: "hint below the x-taler-bank field")
+                            .talerFont(.body)
+                            .foregroundColor(.red)
+                            .padding(.bottom)
+                    }
                 } else {
                     Text("unknown payment method")
                         .talerFont(.title3)