diff --git a/BankingUiCommon/src/main/java/net/dankito/banking/util/IBase64Service.kt b/BankingUiCommon/src/main/java/net/dankito/banking/util/IBase64Service.kt
new file mode 100644
index 00000000..1f01c7e8
--- /dev/null
+++ b/BankingUiCommon/src/main/java/net/dankito/banking/util/IBase64Service.kt
@@ -0,0 +1,12 @@
+package net.dankito.banking.util
+
+import java.nio.charset.Charset
+
+
+interface IBase64Service {
+
+    fun encode(text: String, charset: Charset): String
+
+    fun decode(base64: String, charset: Charset): String
+
+}
\ No newline at end of file
diff --git a/fints4javaAndroidApp/src/main/java/net/dankito/banking/fints4java/android/Base64ServiceAndroid.kt b/fints4javaAndroidApp/src/main/java/net/dankito/banking/fints4java/android/Base64ServiceAndroid.kt
index 271cbd89..e07f404b 100644
--- a/fints4javaAndroidApp/src/main/java/net/dankito/banking/fints4java/android/Base64ServiceAndroid.kt
+++ b/fints4javaAndroidApp/src/main/java/net/dankito/banking/fints4java/android/Base64ServiceAndroid.kt
@@ -1,7 +1,7 @@
 package net.dankito.banking.fints4java.android
 
 import android.util.Base64
-import net.dankito.fints.util.IBase64Service
+import net.dankito.banking.util.IBase64Service
 import java.nio.charset.Charset
 
 
diff --git a/fints4javaAndroidApp/src/main/java/net/dankito/banking/fints4java/android/ui/MainWindowPresenter.kt b/fints4javaAndroidApp/src/main/java/net/dankito/banking/fints4java/android/ui/MainWindowPresenter.kt
index 1b2f2185..b5333440 100644
--- a/fints4javaAndroidApp/src/main/java/net/dankito/banking/fints4java/android/ui/MainWindowPresenter.kt
+++ b/fints4javaAndroidApp/src/main/java/net/dankito/banking/fints4java/android/ui/MainWindowPresenter.kt
@@ -1,7 +1,7 @@
 package net.dankito.banking.fints4java.android.ui
 
-import net.dankito.banking.ui.IBankingClient
 import net.dankito.banking.ui.BankingClientCallback
+import net.dankito.banking.ui.IBankingClient
 import net.dankito.banking.ui.model.Account
 import net.dankito.banking.ui.model.AccountTransaction
 import net.dankito.banking.ui.model.BankAccount
@@ -9,9 +9,10 @@ import net.dankito.banking.ui.model.parameters.TransferMoneyData
 import net.dankito.banking.ui.model.responses.AddAccountResponse
 import net.dankito.banking.ui.model.responses.BankingClientResponse
 import net.dankito.banking.ui.model.responses.GetTransactionsResponse
+import net.dankito.banking.util.IBase64Service
+import net.dankito.banking.util.UiCommonBase64ServiceWrapper
 import net.dankito.fints.banks.BankFinder
 import net.dankito.fints.model.BankInfo
-import net.dankito.fints.util.IBase64Service
 import net.dankito.utils.IThreadPool
 import net.dankito.utils.ThreadPool
 import net.dankito.utils.web.client.OkHttpWebClient
@@ -44,7 +45,7 @@ open class MainWindowPresenter(protected val base64Service: IBase64Service,
     // TODO: move BankInfo out of fints4javaLib
     open fun addAccountAsync(bankInfo: BankInfo, customerId: String, pin: String, callback: (AddAccountResponse) -> Unit) {
 
-        val newClient = net.dankito.banking.fints4javaBankingClient(bankInfo, customerId, pin, OkHttpWebClient(), base64Service, threadPool, this.callback)
+        val newClient = net.dankito.banking.fints4javaBankingClient(bankInfo, customerId, pin, OkHttpWebClient(), UiCommonBase64ServiceWrapper(base64Service), threadPool, this.callback)
 
         newClient.addAccountAsync { response ->
             val account = response.account
diff --git a/fints4javaBankingClient/src/main/kotlin/net/dankito/banking/util/UiCommonBase64ServiceWrapper.kt b/fints4javaBankingClient/src/main/kotlin/net/dankito/banking/util/UiCommonBase64ServiceWrapper.kt
new file mode 100644
index 00000000..602e355a
--- /dev/null
+++ b/fints4javaBankingClient/src/main/kotlin/net/dankito/banking/util/UiCommonBase64ServiceWrapper.kt
@@ -0,0 +1,16 @@
+package net.dankito.banking.util
+
+import java.nio.charset.Charset
+
+
+open class UiCommonBase64ServiceWrapper(protected val base64Service: IBase64Service) : net.dankito.fints.util.IBase64Service {
+
+    override fun encode(text: String, charset: Charset): String {
+        return base64Service.encode(text, charset)
+    }
+
+    override fun decode(base64: String, charset: Charset): String {
+        return base64Service.decode(base64, charset)
+    }
+
+}
\ No newline at end of file