diff --git a/src/Models/Sede.php b/src/Models/Sede.php
index 34b1151..8864d31 100644
--- a/src/Models/Sede.php
+++ b/src/Models/Sede.php
@@ -10,7 +10,7 @@
 class Sede extends Model
 {
     public string $Indirizzo;
-    public string $Cap;
+    public string $CAP;
     public string $Comune;
     public ?string $Provincia;
     public ?string $Nazione;
diff --git a/tests/IdTest.php b/tests/IdTest.php
new file mode 100644
index 0000000..65c880c
--- /dev/null
+++ b/tests/IdTest.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Axiostudio\FatturaElettronica\Tests;
+
+use Axiostudio\FatturaElettronica\Models\Id;
+use Axiostudio\FatturaElettronica\Settings;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Validator\Validation;
+
+class IdTest extends TestCase
+{
+    public function testConstructorWithIdPaese(): void
+    {
+        $idCodice = 'ABC123456789';
+        $idPaese = 'IT';
+
+        $id = new Id($idCodice, $idPaese);
+
+        $this->assertInstanceOf(Id::class, $id);
+        $this->assertEquals($idCodice, $id->IdCodice);
+        $this->assertEquals($idPaese, $id->IdPaese);
+    }
+
+    public function testConstructorWithoutIdPaese(): void
+    {
+        $idCodice = 'ABC123456789';
+
+        $id = new Id($idCodice);
+
+        $this->assertInstanceOf(Id::class, $id);
+        $this->assertEquals($idCodice, $id->IdCodice);
+        $this->assertEquals(Settings::IdPaeseDefault(), $id->IdPaese);
+    }
+
+    public function testValidation(): void
+    {
+        $id = new Id('ABC123456789', 'IT');
+
+        $validator = Validation::createValidatorBuilder()->enableAnnotationMapping()->getValidator();
+
+        $violations = $validator->validate($id);
+
+        $this->assertCount(0, $violations);
+    }
+}
diff --git a/tests/SedeTest.php b/tests/SedeTest.php
new file mode 100644
index 0000000..b981387
--- /dev/null
+++ b/tests/SedeTest.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Axiostudio\FatturaElettronica\Tests;
+
+use Axiostudio\FatturaElettronica\Models\Sede;
+use Axiostudio\FatturaElettronica\Settings;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Validator\Validation;
+
+class SedeTest extends TestCase
+{
+    public function testConstructorWithProvinciaAndNazione(): void
+    {
+        $indirizzo = 'Via Example, 123';
+        $cap = '12345';
+        $comune = 'Example City';
+        $provincia = 'EX';
+        $nazione = 'IT';
+
+        $sede = new Sede($indirizzo, $cap, $comune, $provincia, $nazione);
+
+        $this->assertInstanceOf(Sede::class, $sede);
+        $this->assertEquals($indirizzo, $sede->Indirizzo);
+        $this->assertEquals($cap, $sede->CAP);
+        $this->assertEquals($comune, $sede->Comune);
+        $this->assertEquals($provincia, $sede->Provincia);
+        $this->assertEquals($nazione, $sede->Nazione);
+    }
+
+    public function testConstructorWithoutProvinciaAndNazione(): void
+    {
+        $indirizzo = 'Via Example, 123';
+        $cap = '12345';
+        $comune = 'Example City';
+
+        $sede = new Sede($indirizzo, $cap, $comune);
+
+        $this->assertInstanceOf(Sede::class, $sede);
+        $this->assertEquals($indirizzo, $sede->Indirizzo);
+        $this->assertEquals($cap, $sede->CAP);
+        $this->assertEquals($comune, $sede->Comune);
+        $this->assertNull($sede->Provincia);
+        $this->assertEquals(Settings::IdPaeseDefault(), $sede->Nazione);
+    }
+
+    public function testValidation(): void
+    {
+        $sede = new Sede('Via Example, 123', '12345', 'Example City', 'EX', 'IT');
+
+        $validator = Validation::createValidatorBuilder()->enableAnnotationMapping()->getValidator();
+
+        $violations = $validator->validate($sede);
+
+        $this->assertCount(0, $violations);
+    }
+}