diff --git a/Tests/Unit/Action/GetStatementOfAccountTest.php b/Tests/Unit/Action/GetStatementOfAccountTest.php
new file mode 100644
index 00000000..fcbcf17f
--- /dev/null
+++ b/Tests/Unit/Action/GetStatementOfAccountTest.php
@@ -0,0 +1,163 @@
+<?php
+
+namespace Fhp\Tests\Unit\Action;
+
+use Fhp\Action\GetStatementOfAccount;
+use Fhp\Model\SEPAAccount;
+use Fhp\Protocol\BPD;
+use Fhp\Segment\BaseSegment;
+use Fhp\Segment\KAZ\HIKAZSv5;
+use Fhp\Segment\KAZ\HIKAZSv6;
+use Fhp\Segment\KAZ\HIKAZSv7;
+use Fhp\Segment\KAZ\HKKAZv5;
+use Fhp\Segment\KAZ\HKKAZv7;
+use Fhp\Segment\KAZ\ParameterKontoumsaetzeV2;
+use Fhp\Segment\SPA\HISPASv1;
+use Fhp\Segment\SPA\ParameterSepaKontoverbindungAnfordernV1;
+
+class GetStatementOfAccountTest extends \PHPUnit\Framework\TestCase
+{
+    public function testRejectsReversedDateRange()
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        GetStatementOfAccount::create(
+            self::account(),
+            new \DateTimeImmutable('2026-07-19'),
+            new \DateTimeImmutable('2026-04-20')
+        );
+    }
+
+    public function testCreateRequestBuildsHkkazV5FromDateTimeInterface()
+    {
+        $action = GetStatementOfAccount::create(
+            self::account(),
+            new \DateTimeImmutable('2026-04-20'),
+            new \DateTimeImmutable('2026-07-19'),
+            true
+        );
+
+        $requestSegments = $action->getNextRequest(self::createBpd(self::createHikazsSegment(5, true)), null);
+
+        $this->assertCount(1, $requestSegments);
+        /** @var HKKAZv5 $request */
+        $request = $requestSegments[0];
+        self::assertInstanceOf(HKKAZv5::class, $request);
+        self::assertTrue($request->alleKonten);
+        self::assertSame('20260420', $request->vonDatum);
+        self::assertSame('20260719', $request->bisDatum);
+        self::assertSame('5407324931', $request->kontoverbindungAuftraggeber->kontonummer);
+        self::assertSame('50010517', $request->kontoverbindungAuftraggeber->kik->kreditinstitutscode);
+    }
+
+    public function testCreateRequestBuildsHkkazV7FromDateTimeInterface()
+    {
+        $action = GetStatementOfAccount::create(
+            self::account(),
+            new \DateTimeImmutable('2026-04-20'),
+            new \DateTimeImmutable('2026-07-19'),
+            true
+        );
+
+        $bpd = self::createBpd(
+            self::createHikazsSegment(7, true),
+            self::createHispasSegment(true)
+        );
+        $requestSegments = $action->getNextRequest($bpd, null);
+
+        self::assertCount(1, $requestSegments);
+        /** @var HKKAZv7 $request */
+        $request = $requestSegments[0];
+        self::assertInstanceOf(HKKAZv7::class, $request);
+        self::assertTrue($request->alleKonten);
+        self::assertSame('20260420', $request->vonDatum);
+        self::assertSame('20260719', $request->bisDatum);
+        self::assertSame('DE44500105175407324931', $request->kontoverbindungInternational->iban);
+        self::assertSame('INGDDEFFXXX', $request->kontoverbindungInternational->bic);
+        self::assertSame('5407324931', $request->kontoverbindungInternational->kontonummer);
+    }
+
+    public function testCreateRequestRejectsAllAccountsWhenNotSupportedByBank()
+    {
+        $action = GetStatementOfAccount::create(self::account(), null, null, true);
+
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('allAccounts=true');
+        $action->getNextRequest(self::createBpd(self::createHikazsSegment(6, false)), null);
+    }
+
+    private static function account(): SEPAAccount
+    {
+        return (new SEPAAccount())
+            ->setIban('DE44500105175407324931')
+            ->setBic('INGDDEFFXXX')
+            ->setAccountNumber('5407324931')
+            ->setBlz('50010517');
+    }
+
+    private static function parameterKontoumsaetze(bool $allAccountsAllowed): ParameterKontoumsaetzeV2
+    {
+        $parameter = new ParameterKontoumsaetzeV2();
+        $parameter->speicherzeitraum = 90;
+        $parameter->eingabeAnzahlEintraegeErlaubt = false;
+        $parameter->alleKontenErlaubt = $allAccountsAllowed;
+        return $parameter;
+    }
+
+    private static function createHikazsSegment(int $version, bool $allAccountsAllowed): HIKAZSv5|HIKAZSv6|HIKAZSv7
+    {
+        switch ($version) {
+            case 5:
+                $segment = HIKAZSv5::createEmpty();
+                break;
+            case 6:
+                $segment = HIKAZSv6::createEmpty();
+                break;
+            case 7:
+                $segment = HIKAZSv7::createEmpty();
+                break;
+            default:
+                throw new \InvalidArgumentException("Unsupported test HIKAZS version $version");
+        }
+
+        $segment->maximaleAnzahlAuftraege = 1;
+        $segment->anzahlSignaturenMindestens = 1;
+        if (!$segment instanceof HIKAZSv5) {
+            $segment->sicherheitsklasse = 0;
+        }
+        $segment->parameter = self::parameterKontoumsaetze($allAccountsAllowed);
+        return $segment;
+    }
+
+    private static function createHispasSegment(bool $nationalAccountAllowed): HISPASv1
+    {
+        $parameter = new ParameterSepaKontoverbindungAnfordernV1();
+        $parameter->einzelkontenabrufErlaubt = true;
+        $parameter->nationaleKontoverbindungErlaubt = $nationalAccountAllowed;
+        $parameter->strukturierterVerwendungszweckErlaubt = false;
+        $parameter->unterstuetzteSepaDatenformate = ['urn:iso:std:iso:20022:tech:xsd:pain.001.001.03'];
+
+        $segment = HISPASv1::createEmpty();
+        $segment->maximaleAnzahlAuftraege = 1;
+        $segment->anzahlSignaturenMindestens = 1;
+        $segment->sicherheitsklasse = 0;
+        $segment->parameter = $parameter;
+        return $segment;
+    }
+
+    private static function createBpd(BaseSegment $hikazs, ?BaseSegment $hispas = null): BPD
+    {
+        $bpd = new class extends BPD {
+            public function getBankName()
+            {
+                return 'Testbank';
+            }
+        };
+
+        $bpd->parameters['HIKAZS'][$hikazs->getVersion()] = $hikazs;
+        if ($hispas !== null) {
+            $bpd->parameters['HISPAS'][$hispas->getVersion()] = $hispas;
+        }
+
+        return $bpd;
+    }
+}
diff --git a/src/Segment/CAZ/HKCAZv1.php b/src/Segment/CAZ/HKCAZv1.php
index ecaabf2b..f2001aac 100644
--- a/src/Segment/CAZ/HKCAZv1.php
+++ b/src/Segment/CAZ/HKCAZv1.php
@@ -28,7 +28,7 @@ class HKCAZv1 extends BaseSegment implements Paginateable
     public ?string $aufsetzpunkt = null;
 
     public static function create(\Fhp\Segment\Common\Kti $kti, UnterstuetzteCamtMessages $unterstuetzteCamtMessages,
-        bool $alleKonten, ?\DateTime $vonDatum, ?\DateTime $bisDatum, ?string $aufsetzpunkt = null): HKCAZv1
+        bool $alleKonten, ?\DateTimeInterface $vonDatum, ?\DateTimeInterface $bisDatum, ?string $aufsetzpunkt = null): HKCAZv1
     {
         $result = HKCAZv1::createEmpty();
         $result->kontoverbindungInternational = $kti;
diff --git a/src/Segment/KAZ/HKKAZv4.php b/src/Segment/KAZ/HKKAZv4.php
index 9b612b80..7b01bd28 100644
--- a/src/Segment/KAZ/HKKAZv4.php
+++ b/src/Segment/KAZ/HKKAZv4.php
@@ -26,7 +26,7 @@ class HKKAZv4 extends BaseSegment implements Paginateable
     /** Max length: 35 */
     public ?string $aufsetzpunkt = null;
 
-    public static function create(\Fhp\Segment\Common\Kto $kto, ?\DateTime $vonDatum, ?\DateTime $bisDatum, ?string $aufsetzpunkt = null): HKKAZv4
+    public static function create(\Fhp\Segment\Common\Kto $kto, ?\DateTimeInterface $vonDatum, ?\DateTimeInterface $bisDatum, ?string $aufsetzpunkt = null): HKKAZv4
     {
         $result = HKKAZv4::createEmpty();
         $result->kontoverbindungAuftraggeber = $kto;
diff --git a/src/Segment/KAZ/HKKAZv5.php b/src/Segment/KAZ/HKKAZv5.php
index 8360c23e..dae9e536 100644
--- a/src/Segment/KAZ/HKKAZv5.php
+++ b/src/Segment/KAZ/HKKAZv5.php
@@ -27,7 +27,7 @@ class HKKAZv5 extends BaseSegment implements Paginateable
     /** Max length: 35 */
     public ?string $aufsetzpunkt = null;
 
-    public static function create(\Fhp\Segment\Common\KtvV3 $ktv, bool $alleKonten, ?\DateTime $vonDatum, ?\DateTime $bisDatum, ?string $aufsetzpunkt = null): HKKAZv5
+    public static function create(\Fhp\Segment\Common\KtvV3 $ktv, bool $alleKonten, ?\DateTimeInterface $vonDatum, ?\DateTimeInterface $bisDatum, ?string $aufsetzpunkt = null): HKKAZv5
     {
         $result = HKKAZv5::createEmpty();
         $result->kontoverbindungAuftraggeber = $ktv;
diff --git a/src/Segment/KAZ/HKKAZv6.php b/src/Segment/KAZ/HKKAZv6.php
index d84f6af4..84af1679 100644
--- a/src/Segment/KAZ/HKKAZv6.php
+++ b/src/Segment/KAZ/HKKAZv6.php
@@ -26,7 +26,7 @@ class HKKAZv6 extends BaseSegment implements Paginateable
     /** Max length: 35 */
     public ?string $aufsetzpunkt = null;
 
-    public static function create(\Fhp\Segment\Common\KtvV3 $ktv, bool $alleKonten, ?\DateTime $vonDatum, ?\DateTime $bisDatum, ?string $aufsetzpunkt = null): HKKAZv6
+    public static function create(\Fhp\Segment\Common\KtvV3 $ktv, bool $alleKonten, ?\DateTimeInterface $vonDatum, ?\DateTimeInterface $bisDatum, ?string $aufsetzpunkt = null): HKKAZv6
     {
         $result = HKKAZv6::createEmpty();
         $result->kontoverbindungAuftraggeber = $ktv;
diff --git a/src/Segment/KAZ/HKKAZv7.php b/src/Segment/KAZ/HKKAZv7.php
index 23d62831..134c6976 100644
--- a/src/Segment/KAZ/HKKAZv7.php
+++ b/src/Segment/KAZ/HKKAZv7.php
@@ -26,7 +26,7 @@ class HKKAZv7 extends BaseSegment implements Paginateable
     /** Max length: 35 */
     public ?string $aufsetzpunkt = null;
 
-    public static function create(\Fhp\Segment\Common\Kti $kti, bool $alleKonten, ?\DateTime $vonDatum, ?\DateTime $bisDatum, ?string $aufsetzpunkt = null): HKKAZv7
+    public static function create(\Fhp\Segment\Common\Kti $kti, bool $alleKonten, ?\DateTimeInterface $vonDatum, ?\DateTimeInterface $bisDatum, ?string $aufsetzpunkt = null): HKKAZv7
     {
         $result = HKKAZv7::createEmpty();
         $result->kontoverbindungInternational = $kti;