diff --git a/fints4javaLib/src/main/kotlin/net/dankito/fints/FinTsClient.kt b/fints4javaLib/src/main/kotlin/net/dankito/fints/FinTsClient.kt
index a92f22aa..90249ff3 100644
--- a/fints4javaLib/src/main/kotlin/net/dankito/fints/FinTsClient.kt
+++ b/fints4javaLib/src/main/kotlin/net/dankito/fints/FinTsClient.kt
@@ -20,6 +20,7 @@ import net.dankito.utils.web.client.RequestParameters
 import net.dankito.utils.web.client.WebClientResponse
 import org.slf4j.LoggerFactory
 import java.math.BigDecimal
+import java.util.*
 
 
 open class FinTsClient @JvmOverloads constructor(
@@ -82,8 +83,48 @@ open class FinTsClient @JvmOverloads constructor(
     }
 
 
+    /**
+     * Some banks support that according to PSD2 account transactions may be retrieved without
+     * a TAN (= no strong customer authorization needed).
+     */
+    open fun tryGetTransactionsOfLast90DaysWithoutTanAsync(bank: BankData, customer: CustomerData,
+                                                           callback: (GetTransactionsResponse) -> Unit) {
+
+        callback(tryGetTransactionsOfLast90DaysWithoutTan(bank, customer, false))
+    }
+
+    /**
+     * Some banks support that according to PSD2 account transactions may be retrieved without
+     * a TAN (= no strong customer authorization needed).
+     */
+    open fun tryGetTransactionsOfLast90DaysWithoutTan(bank: BankData, customer: CustomerData): GetTransactionsResponse {
+
+        return tryGetTransactionsOfLast90DaysWithoutTan(bank, customer, false)
+    }
+
+    protected open fun tryGetTransactionsOfLast90DaysWithoutTan(bank: BankData, customer: CustomerData,
+                                                      skipSettingCustomerFlag: Boolean): GetTransactionsResponse {
+
+        val ninetyDaysAgoMilliseconds = 90 * 24 * 60 * 60 * 1000L
+        val ninetyDaysAgo = Date(Date().time - ninetyDaysAgoMilliseconds)
+
+        val response = getTransactions(
+            GetTransactionsParameter(false, ninetyDaysAgo), bank, customer)
+
+        customer.triedToRetrieveTransactionsOfLast90DaysWithoutTan = true
+
+        if (response.isSuccessful) {
+            if (skipSettingCustomerFlag == false) {
+                customer.supportsRetrievingTransactionsOfLast90DaysWithoutTan =
+                    response.isStrongAuthenticationRequired
+            }
+        }
+
+        return response
+    }
+
     open fun getTransactionsAsync(parameter: GetTransactionsParameter, bank: BankData,
-                                 customer: CustomerData, callback: (GetTransactionsResponse) -> Unit) {
+                                  customer: CustomerData, callback: (GetTransactionsResponse) -> Unit) {
 
         threadPool.runAsync {
             callback(getTransactions(parameter, bank, customer))
@@ -95,6 +136,12 @@ open class FinTsClient @JvmOverloads constructor(
 
 //        synchronizeCustomerSystemIdIfNotDoneYet(bank, customer) // even though specification says this is required it can be omitted
 
+        if (customer.supportsRetrievingTransactionsOfLast90DaysWithoutTan == null &&
+                customer.triedToRetrieveTransactionsOfLast90DaysWithoutTan == false &&
+                parameter.fromDate == null) {
+            tryGetTransactionsOfLast90DaysWithoutTan(bank, customer, true)
+        }
+
 
         val dialogData = DialogData()
 
@@ -130,6 +177,13 @@ open class FinTsClient @JvmOverloads constructor(
 
 
         response.getFirstSegmentById<ReceivedAccountTransactions>(InstituteSegmentId.AccountTransactionsMt940)?.let { transactions ->
+            // TODO: that should not work. Find out in which method transactions are retrieved after entering TAN
+            // just retrieved all transactions -> check if retrieving that ones of last 90 days is possible without entering TAN
+            if (customer.supportsRetrievingTransactionsOfLast90DaysWithoutTan == null &&
+                response.successful && transactions.bookedTransactions.isNotEmpty() && parameter.fromDate == null) {
+                tryGetTransactionsOfLast90DaysWithoutTan(bank, customer)
+            }
+
             return GetTransactionsResponse(response,
                 transactions.bookedTransactions.sortedByDescending { it.bookingDate },
                 transactions.unbookedTransactions,
diff --git a/fints4javaLib/src/main/kotlin/net/dankito/fints/model/CustomerData.kt b/fints4javaLib/src/main/kotlin/net/dankito/fints/model/CustomerData.kt
index 5ddb424f..fba2d251 100644
--- a/fints4javaLib/src/main/kotlin/net/dankito/fints/model/CustomerData.kt
+++ b/fints4javaLib/src/main/kotlin/net/dankito/fints/model/CustomerData.kt
@@ -19,7 +19,9 @@ open class CustomerData(
     var version: VersionDesSicherheitsverfahrens = VersionDesSicherheitsverfahrens.PIN_Zwei_Schritt,
     var selectedLanguage: Dialogsprache = Dialogsprache.Default,
     var customerSystemId: String = KundensystemID.Anonymous,
-    var customerSystemStatus: KundensystemStatusWerte = KundensystemStatus.SynchronizingCustomerSystemId
+    var customerSystemStatus: KundensystemStatusWerte = KundensystemStatus.SynchronizingCustomerSystemId,
+    var supportsRetrievingTransactionsOfLast90DaysWithoutTan: Boolean? = null,
+    var triedToRetrieveTransactionsOfLast90DaysWithoutTan: Boolean = false
 ) {
 
     companion object {
diff --git a/fints4javaLib/src/test/kotlin/net/dankito/fints/FinTsClientTest.kt b/fints4javaLib/src/test/kotlin/net/dankito/fints/FinTsClientTest.kt
index 81390d53..f323dbdf 100644
--- a/fints4javaLib/src/test/kotlin/net/dankito/fints/FinTsClientTest.kt
+++ b/fints4javaLib/src/test/kotlin/net/dankito/fints/FinTsClientTest.kt
@@ -11,7 +11,6 @@ import net.dankito.fints.util.Java8Base64Service
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.Ignore
 import org.junit.Test
-import java.util.*
 
 
 @Ignore // not an automatic test, supply your settings below
@@ -66,13 +65,11 @@ class FinTsClientTest {
     @Test
     fun getTransactions() {
 
-        // given
-        // some banks support retrieving account transactions of last 90 days without TAN
-        val ninetyDaysAgoMilliseconds = 90 * 24 * 60 * 60 * 1000L
-        val ninetyDaysAgo = Date(Date().time - ninetyDaysAgoMilliseconds)
-
         // when
-        val result = underTest.getTransactions(GetTransactionsParameter(fromDate = ninetyDaysAgo), Bank, Customer)
+
+        // some banks support retrieving account transactions of last 90 days without TAN
+        val result = underTest.tryGetTransactionsOfLast90DaysWithoutTan(Bank, Customer)
+
 
         // then
         assertThat(result.isSuccessful).isTrue()