diff --git a/fints4javaLib/src/main/kotlin/net/dankito/fints/callback/NoOpFinTsClientCallback.kt b/fints4javaLib/src/main/kotlin/net/dankito/fints/callback/NoOpFinTsClientCallback.kt
new file mode 100644
index 00000000..af7f2fbe
--- /dev/null
+++ b/fints4javaLib/src/main/kotlin/net/dankito/fints/callback/NoOpFinTsClientCallback.kt
@@ -0,0 +1,23 @@
+package net.dankito.fints.callback
+
+import net.dankito.fints.messages.datenelemente.implementierte.tan.TanGeneratorTanMedium
+import net.dankito.fints.model.*
+
+
+open class NoOpFinTsClientCallback : FinTsClientCallback {
+
+    override fun askUserForTanProcedure(supportedTanProcedures: List<TanProcedure>,
+                                        suggestedTanProcedure: TanProcedure?): TanProcedure? {
+
+        return suggestedTanProcedure
+    }
+
+    override fun enterTan(customer: CustomerData, tanChallenge: TanChallenge): EnterTanResult {
+        return EnterTanResult.userDidNotEnterTan()
+    }
+
+    override fun enterTanGeneratorAtc(customer: CustomerData, tanMedium: TanGeneratorTanMedium): EnterTanGeneratorAtcResult {
+        return EnterTanGeneratorAtcResult.userDidNotEnterTan()
+    }
+
+}
\ No newline at end of file
diff --git a/fints4javaLib/src/main/kotlin/net/dankito/fints/callback/SimpleFinTsClientCallback.kt b/fints4javaLib/src/main/kotlin/net/dankito/fints/callback/SimpleFinTsClientCallback.kt
new file mode 100644
index 00000000..cb08f5e9
--- /dev/null
+++ b/fints4javaLib/src/main/kotlin/net/dankito/fints/callback/SimpleFinTsClientCallback.kt
@@ -0,0 +1,27 @@
+package net.dankito.fints.callback
+
+import net.dankito.fints.messages.datenelemente.implementierte.tan.TanGeneratorTanMedium
+import net.dankito.fints.model.*
+
+
+open class SimpleFinTsClientCallback(
+    protected val enterTan: ((customer: CustomerData, tanChallenge: TanChallenge) -> EnterTanResult)? = null,
+    protected val enterTanGeneratorAtc: ((customer: CustomerData, tanMedium: TanGeneratorTanMedium) -> EnterTanGeneratorAtcResult)? = null,
+    protected val askUserForTanProcedure: ((supportedTanProcedures: List<TanProcedure>, suggestedTanProcedure: TanProcedure?) -> TanProcedure?)? = null
+) : FinTsClientCallback {
+
+    override fun askUserForTanProcedure(supportedTanProcedures: List<TanProcedure>,
+                                        suggestedTanProcedure: TanProcedure?): TanProcedure? {
+
+        return askUserForTanProcedure?.invoke(supportedTanProcedures, suggestedTanProcedure) ?: suggestedTanProcedure
+    }
+
+    override fun enterTan(customer: CustomerData, tanChallenge: TanChallenge): EnterTanResult {
+        return enterTan?.invoke(customer, tanChallenge) ?: EnterTanResult.userDidNotEnterTan()
+    }
+
+    override fun enterTanGeneratorAtc(customer: CustomerData, tanMedium: TanGeneratorTanMedium): EnterTanGeneratorAtcResult {
+        return enterTanGeneratorAtc?.invoke(customer, tanMedium) ?: EnterTanGeneratorAtcResult.userDidNotEnterTan()
+    }
+
+}
\ No newline at end of file