diff --git a/src/Relations/BelongsToMany.php b/src/Relations/BelongsToMany.php
index 082f95e06..8ff311f3f 100644
--- a/src/Relations/BelongsToMany.php
+++ b/src/Relations/BelongsToMany.php
@@ -183,13 +183,13 @@ public function attach($id, array $attributes = [], $touch = true)
         if ($id instanceof Model) {
             $model = $id;
 
-            $id = $model->getKey();
+            $id = $this->parseId($model);
 
             // Attach the new parent id to the related model.
-            $model->push($this->foreignPivotKey, $this->parent->getKey(), true);
+            $model->push($this->foreignPivotKey, $this->parent->{$this->parentKey}, true);
         } else {
             if ($id instanceof Collection) {
-                $id = $id->modelKeys();
+                $id = $this->parseIds($id);
             }
 
             $query = $this->newRelatedQuery();
@@ -221,7 +221,7 @@ public function attach($id, array $attributes = [], $touch = true)
     public function detach($ids = [], $touch = true)
     {
         if ($ids instanceof Model) {
-            $ids = (array) $ids->getKey();
+            $ids = $this->parseIds($ids);
         }
 
         $query = $this->newRelatedQuery();
@@ -242,13 +242,13 @@ public function detach($ids = [], $touch = true)
 
         // Prepare the query to select all related objects.
         if (count($ids) > 0) {
-            $query->whereIn($this->related->getKeyName(), $ids);
+            $query->whereIn($this->relatedKey, $ids);
         }
 
         // Remove the relation to the parent.
         assert($this->parent instanceof Model);
         assert($query instanceof \MongoDB\Laravel\Eloquent\Builder);
-        $query->pull($this->foreignPivotKey, $this->parent->getKey());
+        $query->pull($this->foreignPivotKey, $this->parent->{$this->parentKey});
 
         if ($touch) {
             $this->touchIfTouching();
diff --git a/tests/Models/Client.php b/tests/Models/Client.php
index 2ab4f5e33..4e7e7ecc9 100644
--- a/tests/Models/Client.php
+++ b/tests/Models/Client.php
@@ -20,6 +20,17 @@ public function users(): BelongsToMany
         return $this->belongsToMany(User::class);
     }
 
+    public function skillsWithCustomKeys()
+    {
+        return $this->belongsToMany(
+            Skill::class,
+            foreignPivotKey: 'cclient_ids',
+            relatedPivotKey: 'cskill_ids',
+            parentKey: 'cclient_id',
+            relatedKey: 'cskill_id',
+        );
+    }
+
     public function photo(): MorphOne
     {
         return $this->morphOne(Photo::class, 'has_image');
diff --git a/tests/Models/Experience.php b/tests/Models/Experience.php
index 4c2869d9e..2852ece5f 100644
--- a/tests/Models/Experience.php
+++ b/tests/Models/Experience.php
@@ -15,16 +15,6 @@ class Experience extends Eloquent
 
     protected $casts = ['years' => 'int'];
 
-    public function skillsWithCustomRelatedKey()
-    {
-        return $this->belongsToMany(Skill::class, relatedKey: 'cskill_id');
-    }
-
-    public function skillsWithCustomParentKey()
-    {
-        return $this->belongsToMany(Skill::class, parentKey: 'cexperience_id');
-    }
-
     public function sqlUsers(): MorphToMany
     {
         return $this->morphToMany(SqlUser::class, 'experienced');
diff --git a/tests/RelationsTest.php b/tests/RelationsTest.php
index 652f3d7bf..8c0a7a4a7 100644
--- a/tests/RelationsTest.php
+++ b/tests/RelationsTest.php
@@ -10,7 +10,6 @@
 use MongoDB\Laravel\Tests\Models\Address;
 use MongoDB\Laravel\Tests\Models\Book;
 use MongoDB\Laravel\Tests\Models\Client;
-use MongoDB\Laravel\Tests\Models\Experience;
 use MongoDB\Laravel\Tests\Models\Group;
 use MongoDB\Laravel\Tests\Models\Item;
 use MongoDB\Laravel\Tests\Models\Label;
@@ -36,7 +35,6 @@ public function tearDown(): void
         Photo::truncate();
         Label::truncate();
         Skill::truncate();
-        Experience::truncate();
     }
 
     public function testHasMany(): void
@@ -350,48 +348,226 @@ public function testBelongsToManyAttachEloquentCollection(): void
         $this->assertCount(2, $user->clients);
     }
 
-    public function testBelongsToManySyncEloquentCollectionWithCustomRelatedKey(): void
+    public function testBelongsToManySyncWithCustomKeys(): void
     {
-        $experience = Experience::create(['years' => '5']);
+        $client = Client::create(['cclient_id' => (string) (new ObjectId()), 'years' => '5']);
+        $skill1    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'PHP']);
+        $skill2    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'Laravel']);
+
+        $client = Client::query()->find($client->_id);
+        $client->skillsWithCustomKeys()->sync([$skill1->cskill_id, $skill2->cskill_id]);
+        $this->assertCount(2, $client->skillsWithCustomKeys);
+
+        self::assertIsString($skill1->cskill_id);
+        self::assertContains($skill1->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill1->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        self::assertIsString($skill2->cskill_id);
+        self::assertContains($skill2->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill2->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill1->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill2->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+    }
+
+    public function testBelongsToManySyncModelWithCustomKeys(): void
+    {
+        $client = Client::create(['cclient_id' => (string) (new ObjectId()), 'years' => '5']);
+        $skill1    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'PHP']);
+
+        $client = Client::query()->find($client->_id);
+        $client->skillsWithCustomKeys()->sync($skill1);
+        $this->assertCount(1, $client->skillsWithCustomKeys);
+
+        self::assertIsString($skill1->cskill_id);
+        self::assertContains($skill1->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill1->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill1->_id);
+        self::assertIsString($check->_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+    }
+
+    public function testBelongsToManySyncEloquentCollectionWithCustomKeys(): void
+    {
+        $client = Client::create(['cclient_id' => (string) (new ObjectId()), 'years' => '5']);
         $skill1    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'PHP']);
         $skill2    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'Laravel']);
         $collection = new Collection([$skill1, $skill2]);
 
-        $experience = Experience::query()->find($experience->id);
-        $experience->skillsWithCustomRelatedKey()->sync($collection);
-        $this->assertCount(2, $experience->skillsWithCustomRelatedKey);
+        $client = Client::query()->find($client->_id);
+        $client->skillsWithCustomKeys()->sync($collection);
+        $this->assertCount(2, $client->skillsWithCustomKeys);
 
         self::assertIsString($skill1->cskill_id);
-        self::assertContains($skill1->cskill_id, $experience->skillsWithCustomRelatedKey->pluck('cskill_id'));
+        self::assertContains($skill1->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill1->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
 
         self::assertIsString($skill2->cskill_id);
-        self::assertContains($skill2->cskill_id, $experience->skillsWithCustomRelatedKey->pluck('cskill_id'));
+        self::assertContains($skill2->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill2->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill1->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill2->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+    }
+
+    public function testBelongsToManyAttachWithCustomKeys(): void
+    {
+        $client = Client::create(['cclient_id' => (string) (new ObjectId()), 'years' => '5']);
+        $skill1    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'PHP']);
+        $skill2    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'Laravel']);
+
+        $client = Client::query()->find($client->_id);
+        $client->skillsWithCustomKeys()->attach([$skill1->cskill_id, $skill2->cskill_id]);
+        $this->assertCount(2, $client->skillsWithCustomKeys);
+
+        self::assertIsString($skill1->cskill_id);
+        self::assertContains($skill1->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill1->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        self::assertIsString($skill2->cskill_id);
+        self::assertContains($skill2->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill2->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill1->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill2->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+    }
+
+    public function testBelongsToManyAttachModelWithCustomKeys(): void
+    {
+        $client = Client::create(['cclient_id' => (string) (new ObjectId()), 'years' => '5']);
+        $skill1    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'PHP']);
 
-        $skill1->refresh();
-        self::assertIsString($skill1->_id);
-        self::assertNotContains($skill1->_id, $experience->skillsWithCustomRelatedKey->pluck('cskill_id'));
+        $client = Client::query()->find($client->_id);
+        $client->skillsWithCustomKeys()->attach($skill1);
+        $this->assertCount(1, $client->skillsWithCustomKeys);
+
+        self::assertIsString($skill1->cskill_id);
+        self::assertContains($skill1->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill1->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
 
-        $skill2->refresh();
-        self::assertIsString($skill2->_id);
-        self::assertNotContains($skill2->_id, $experience->skillsWithCustomRelatedKey->pluck('cskill_id'));
+        $check = Skill::query()->find($skill1->_id);
+        self::assertIsString($check->_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
     }
 
-    public function testBelongsToManySyncEloquentCollectionWithCustomParentKey(): void
+    public function testBelongsToManyAttachEloquentCollectionWithCustomKeys(): void
     {
-        $experience = Experience::create(['cexperience_id' => (string) (new ObjectId()), 'years' => '5']);
-        $skill1    = Skill::create(['name' => 'PHP']);
-        $skill2    = Skill::create(['name' => 'Laravel']);
+        $client = Client::create(['cclient_id' => (string) (new ObjectId()), 'years' => '5']);
+        $skill1    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'PHP']);
+        $skill2    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'Laravel']);
         $collection = new Collection([$skill1, $skill2]);
 
-        $experience = Experience::query()->find($experience->id);
-        $experience->skillsWithCustomParentKey()->sync($collection);
-        $this->assertCount(2, $experience->skillsWithCustomParentKey);
+        $client = Client::query()->find($client->_id);
+        $client->skillsWithCustomKeys()->attach($collection);
+        $this->assertCount(2, $client->skillsWithCustomKeys);
+
+        self::assertIsString($skill1->cskill_id);
+        self::assertContains($skill1->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill1->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        self::assertIsString($skill2->cskill_id);
+        self::assertContains($skill2->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill2->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill1->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill2->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+    }
+
+    public function testBelongsToManyDetachWithCustomKeys(): void
+    {
+        $client = Client::create(['cclient_id' => (string) (new ObjectId()), 'years' => '5']);
+        $skill1    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'PHP']);
+        $skill2    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'Laravel']);
+
+        $client = Client::query()->find($client->_id);
+        $client->skillsWithCustomKeys()->sync([$skill1->cskill_id, $skill2->cskill_id]);
+        $this->assertCount(2, $client->skillsWithCustomKeys);
+
+        $client->skillsWithCustomKeys()->detach($skill1->cskill_id);
+        $client->load('skillsWithCustomKeys'); // Reload the relationship based on the latest pivot column's data
+        $this->assertCount(1, $client->skillsWithCustomKeys);
+
+        self::assertIsString($skill1->cskill_id);
+        self::assertNotContains($skill1->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill1->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
 
-        self::assertIsString($skill1->_id);
-        self::assertContains($skill1->_id, $experience->skillsWithCustomParentKey->pluck('_id'));
+        self::assertIsString($skill2->cskill_id);
+        self::assertContains($skill2->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill2->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill1->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertNotContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill2->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+    }
 
-        self::assertIsString($skill2->_id);
-        self::assertContains($skill2->_id, $experience->skillsWithCustomParentKey->pluck('_id'));
+    public function testBelongsToManyDetachModelWithCustomKeys(): void
+    {
+        $client = Client::create(['cclient_id' => (string) (new ObjectId()), 'years' => '5']);
+        $skill1    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'PHP']);
+        $skill2    = Skill::create(['cskill_id' => (string) (new ObjectId()), 'name' => 'Laravel']);
+
+        $client = Client::query()->find($client->_id);
+        $client->skillsWithCustomKeys()->sync([$skill1->cskill_id, $skill2->cskill_id]);
+        $this->assertCount(2, $client->skillsWithCustomKeys);
+
+        $client->skillsWithCustomKeys()->detach($skill1);
+        $client->load('skillsWithCustomKeys'); // Reload the relationship based on the latest pivot column's data
+        $this->assertCount(1, $client->skillsWithCustomKeys);
+
+        self::assertIsString($skill1->cskill_id);
+        self::assertNotContains($skill1->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill1->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        self::assertIsString($skill2->cskill_id);
+        self::assertContains($skill2->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($skill2->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill1->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertNotContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+
+        $check = Skill::query()->find($skill2->_id);
+        self::assertIsString($check->cskill_id);
+        self::assertContains($check->cskill_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
+        self::assertNotContains($check->_id, $client->skillsWithCustomKeys->pluck('cskill_id'));
     }
 
     public function testBelongsToManySyncAlreadyPresent(): void