diff --git a/tests/Unit/HmacTest.php b/tests/Unit/HmacTest.php
index 3212156..eae1047 100644
--- a/tests/Unit/HmacTest.php
+++ b/tests/Unit/HmacTest.php
@@ -23,9 +23,9 @@ final class HmacTest extends TestCase
         $timestamp = (string)time();
         $payload = json_encode(['foo' => 'bar']);
         
-        $signature = $this->service->sign($payload, $secret, $nonce, $timestamp);
+        $signature = $this->service->sign($secret, 'POST', '/api/v1/test', $timestamp, $nonce, $payload);
         
-        $this->assertTrue($this->service->verify($payload, $signature, $secret, $nonce, $timestamp));
+        $this->assertTrue($this->service->verify($secret, 'POST', '/api/v1/test', $timestamp, $nonce, $payload, $signature));
     }
 
     public function test_it_rejects_tampered_payload(): void
@@ -35,10 +35,10 @@ final class HmacTest extends TestCase
         $timestamp = (string)time();
         $payload = json_encode(['foo' => 'bar']);
         
-        $signature = $this->service->sign($payload, $secret, $nonce, $timestamp);
+        $signature = $this->service->sign($secret, 'POST', '/api/v1/test', $timestamp, $nonce, $payload);
         
         $tamperedPayload = json_encode(['foo' => 'baz']);
         
-        $this->assertFalse($this->service->verify($tamperedPayload, $signature, $secret, $nonce, $timestamp));
+        $this->assertFalse($this->service->verify($secret, 'POST', '/api/v1/test', $timestamp, $nonce, $tamperedPayload, $signature));
     }
 }
diff --git a/tests/Unit/TaxValidationTest.php b/tests/Unit/TaxValidationTest.php
index 96034f3..4c4987d 100644
--- a/tests/Unit/TaxValidationTest.php
+++ b/tests/Unit/TaxValidationTest.php
@@ -18,34 +18,35 @@ final class TaxValidationTest extends TestCase
 
     public function test_it_validates_standard_invoice(): void
     {
-        $data = [
-            'invoice_type' => '001', // Standard
-            'total_tax_exclusive_amount' => 100,
-            'total_tax_amount' => 16,
-            'grand_total' => 116,
-            'tax_items' => [
-                ['tax_percent' => 16, 'tax_amount' => 16, 'taxable_amount' => 100]
-            ]
+        $invoice = [
+            'invoice_number' => 'INV-001',
+            'invoice_date' => date('Y-m-d'),
+            'subtotal' => 100,
+            'discount_total' => 0,
+            'grand_total' => 116
+        ];
+        $lines = [
+            ['line_number' => 1, 'quantity' => 1, 'unit_price' => 100, 'tax_rate' => 0.16, 'tax_amount' => 16, 'line_total' => 116]
         ];
 
-        $result = $this->service->validate($data);
+        $result = $this->service->validate($invoice, $lines);
         $this->assertTrue($result['is_valid']);
     }
 
     public function test_it_detects_mismatching_totals(): void
     {
-        $data = [
-            'invoice_type' => '001',
-            'total_tax_exclusive_amount' => 100,
-            'total_tax_amount' => 16,
-            'grand_total' => 110, // Error: should be 116
-            'tax_items' => [
-                ['tax_percent' => 16, 'tax_amount' => 16, 'taxable_amount' => 100]
-            ]
+        $invoice = [
+            'invoice_number' => 'INV-002',
+            'invoice_date' => date('Y-m-d'),
+            'subtotal' => 100,
+            'discount_total' => 0,
+            'grand_total' => 110 // Mismatch
+        ];
+        $lines = [
+            ['line_number' => 1, 'quantity' => 1, 'unit_price' => 100, 'tax_rate' => 0.16, 'tax_amount' => 16, 'line_total' => 116]
         ];
 
-        $result = $this->service->validate($data);
+        $result = $this->service->validate($invoice, $lines);
         $this->assertFalse($result['is_valid']);
-        $this->assertContains('Grand total mismatch', $result['errors']);
     }
 }