diff --git a/api/app/Enums/CrowdListType.php b/api/app/Enums/CrowdListType.php
new file mode 100644
index 00000000..ac3c1c34
--- /dev/null
+++ b/api/app/Enums/CrowdListType.php
@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Enums;
+
+enum CrowdListType: string
+{
+    case INTERNAL = 'internal';
+    case EXTERNAL = 'external';
+}
diff --git a/api/app/Http/Controllers/Api/V1/CrowdListController.php b/api/app/Http/Controllers/Api/V1/CrowdListController.php
index 483ba743..17153df4 100644
--- a/api/app/Http/Controllers/Api/V1/CrowdListController.php
+++ b/api/app/Http/Controllers/Api/V1/CrowdListController.php
@@ -5,24 +5,32 @@ declare(strict_types=1);
 namespace App\Http\Controllers\Api\V1;
 
 use App\Http\Controllers\Controller;
+use App\Http\Requests\Api\V1\AddPersonToCrowdListRequest;
 use App\Http\Requests\Api\V1\StoreCrowdListRequest;
 use App\Http\Requests\Api\V1\UpdateCrowdListRequest;
 use App\Http\Resources\Api\V1\CrowdListResource;
 use App\Models\CrowdList;
 use App\Models\Event;
 use App\Models\Person;
+use App\Services\CrowdListService;
 use Illuminate\Http\JsonResponse;
-use Illuminate\Http\Request;
 use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
 use Illuminate\Support\Facades\Gate;
 
 final class CrowdListController extends Controller
 {
+    public function __construct(
+        private readonly CrowdListService $crowdListService,
+    ) {}
+
     public function index(Event $event): AnonymousResourceCollection
     {
         Gate::authorize('viewAny', [CrowdList::class, $event]);
 
-        $crowdLists = $event->crowdLists()->withCount('persons')->get();
+        $crowdLists = $event->crowdLists()
+            ->with(['crowdType', 'recipientCompany'])
+            ->withCount('persons')
+            ->get();
 
         return CrowdListResource::collection($crowdLists);
     }
@@ -31,43 +39,36 @@ final class CrowdListController extends Controller
     {
         Gate::authorize('create', [CrowdList::class, $event]);
 
-        $crowdList = $event->crowdLists()->create($request->validated());
+        $crowdList = $this->crowdListService->create($event, $request->validated(), $request->user());
 
-        return $this->created(new CrowdListResource($crowdList));
+        return $this->created(new CrowdListResource($crowdList->loadCount('persons')));
     }
 
     public function update(UpdateCrowdListRequest $request, Event $event, CrowdList $crowdList): JsonResponse
     {
         Gate::authorize('update', [$crowdList, $event]);
 
-        $crowdList->update($request->validated());
+        $crowdList = $this->crowdListService->update($crowdList, $request->validated(), $request->user());
 
-        return $this->success(new CrowdListResource($crowdList->fresh()));
+        return $this->success(new CrowdListResource($crowdList->loadCount('persons')));
     }
 
     public function destroy(Event $event, CrowdList $crowdList): JsonResponse
     {
         Gate::authorize('delete', [$crowdList, $event]);
 
-        $crowdList->delete();
+        $this->crowdListService->delete($crowdList, request()->user());
 
         return response()->json(null, 204);
     }
 
-    public function addPerson(Request $request, Event $event, CrowdList $crowdList): JsonResponse
+    public function addPerson(AddPersonToCrowdListRequest $request, Event $event, CrowdList $crowdList): JsonResponse
     {
         Gate::authorize('managePerson', [$crowdList, $event]);
 
-        $validated = $request->validate([
-            'person_id' => ['required', 'ulid', 'exists:persons,id'],
-        ]);
+        $person = Person::findOrFail($request->validated('person_id'));
 
-        $crowdList->persons()->syncWithoutDetaching([
-            $validated['person_id'] => [
-                'added_at' => now(),
-                'added_by_user_id' => $request->user()->id,
-            ],
-        ]);
+        $this->crowdListService->addPerson($crowdList, $person, $request->user());
 
         return $this->success(new CrowdListResource($crowdList->fresh()->loadCount('persons')));
     }
@@ -76,7 +77,7 @@ final class CrowdListController extends Controller
     {
         Gate::authorize('managePerson', [$crowdList, $event]);
 
-        $crowdList->persons()->detach($person->id);
+        $this->crowdListService->removePerson($crowdList, $person, request()->user());
 
         return response()->json(null, 204);
     }
diff --git a/api/app/Http/Requests/Api/V1/AddPersonToCrowdListRequest.php b/api/app/Http/Requests/Api/V1/AddPersonToCrowdListRequest.php
new file mode 100644
index 00000000..3c5076b3
--- /dev/null
+++ b/api/app/Http/Requests/Api/V1/AddPersonToCrowdListRequest.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Requests\Api\V1;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+final class AddPersonToCrowdListRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /** @return array<string, mixed> */
+    public function rules(): array
+    {
+        return [
+            'person_id' => ['required', 'ulid', 'exists:persons,id'],
+        ];
+    }
+}
diff --git a/api/app/Http/Requests/Api/V1/StoreCrowdListRequest.php b/api/app/Http/Requests/Api/V1/StoreCrowdListRequest.php
index 7da7e6d1..b38f88fc 100644
--- a/api/app/Http/Requests/Api/V1/StoreCrowdListRequest.php
+++ b/api/app/Http/Requests/Api/V1/StoreCrowdListRequest.php
@@ -4,7 +4,9 @@ declare(strict_types=1);
 
 namespace App\Http\Requests\Api\V1;
 
+use App\Enums\CrowdListType;
 use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
 
 final class StoreCrowdListRequest extends FormRequest
 {
@@ -19,7 +21,7 @@ final class StoreCrowdListRequest extends FormRequest
         return [
             'crowd_type_id' => ['required', 'ulid', 'exists:crowd_types,id'],
             'name' => ['required', 'string', 'max:255'],
-            'type' => ['required', 'in:internal,external'],
+            'type' => ['required', Rule::enum(CrowdListType::class)],
             'recipient_company_id' => ['nullable', 'ulid', 'exists:companies,id'],
             'auto_approve' => ['sometimes', 'boolean'],
             'max_persons' => ['nullable', 'integer', 'min:1'],
diff --git a/api/app/Http/Requests/Api/V1/UpdateCrowdListRequest.php b/api/app/Http/Requests/Api/V1/UpdateCrowdListRequest.php
index acf2ecdc..9115847e 100644
--- a/api/app/Http/Requests/Api/V1/UpdateCrowdListRequest.php
+++ b/api/app/Http/Requests/Api/V1/UpdateCrowdListRequest.php
@@ -4,7 +4,9 @@ declare(strict_types=1);
 
 namespace App\Http\Requests\Api\V1;
 
+use App\Enums\CrowdListType;
 use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
 
 final class UpdateCrowdListRequest extends FormRequest
 {
@@ -19,7 +21,7 @@ final class UpdateCrowdListRequest extends FormRequest
         return [
             'crowd_type_id' => ['sometimes', 'ulid', 'exists:crowd_types,id'],
             'name' => ['sometimes', 'string', 'max:255'],
-            'type' => ['sometimes', 'in:internal,external'],
+            'type' => ['sometimes', Rule::enum(CrowdListType::class)],
             'recipient_company_id' => ['nullable', 'ulid', 'exists:companies,id'],
             'auto_approve' => ['sometimes', 'boolean'],
             'max_persons' => ['nullable', 'integer', 'min:1'],
diff --git a/api/app/Http/Resources/Api/V1/CrowdListResource.php b/api/app/Http/Resources/Api/V1/CrowdListResource.php
index 00df9c6a..3c7ad07a 100644
--- a/api/app/Http/Resources/Api/V1/CrowdListResource.php
+++ b/api/app/Http/Resources/Api/V1/CrowdListResource.php
@@ -11,17 +11,22 @@ final class CrowdListResource extends JsonResource
 {
     public function toArray(Request $request): array
     {
+        $personsCount = $this->whenCounted('persons');
+
         return [
             'id' => $this->id,
             'event_id' => $this->event_id,
             'crowd_type_id' => $this->crowd_type_id,
             'name' => $this->name,
-            'type' => $this->type,
+            'type' => $this->type->value,
             'recipient_company_id' => $this->recipient_company_id,
             'auto_approve' => $this->auto_approve,
             'max_persons' => $this->max_persons,
+            'is_full' => $this->max_persons !== null && isset($this->persons_count)
+                ? $this->persons_count >= $this->max_persons
+                : false,
             'created_at' => $this->created_at->toIso8601String(),
-            'persons_count' => $this->whenCounted('persons'),
+            'persons_count' => $personsCount,
         ];
     }
 }
diff --git a/api/app/Models/CrowdList.php b/api/app/Models/CrowdList.php
index 4dbc8072..5e504dc3 100644
--- a/api/app/Models/CrowdList.php
+++ b/api/app/Models/CrowdList.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Models;
 
+use App\Enums\CrowdListType;
 use Illuminate\Database\Eloquent\Concerns\HasUlids;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
@@ -28,6 +29,7 @@ final class CrowdList extends Model
     protected function casts(): array
     {
         return [
+            'type' => CrowdListType::class,
             'auto_approve' => 'boolean',
             'max_persons' => 'integer',
         ];
diff --git a/api/app/Services/CrowdListService.php b/api/app/Services/CrowdListService.php
new file mode 100644
index 00000000..2252fd95
--- /dev/null
+++ b/api/app/Services/CrowdListService.php
@@ -0,0 +1,114 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services;
+
+use App\Models\CrowdList;
+use App\Models\Event;
+use App\Models\Person;
+use App\Models\User;
+use Illuminate\Validation\ValidationException;
+
+final class CrowdListService
+{
+    public function create(Event $event, array $data, User $createdBy): CrowdList
+    {
+        $crowdList = $event->crowdLists()->create($data);
+
+        activity('crowd_list')
+            ->causedBy($createdBy)
+            ->performedOn($crowdList)
+            ->withProperties(['attributes' => $crowdList->only($crowdList->getFillable())])
+            ->log('crowd_list.created');
+
+        return $crowdList;
+    }
+
+    public function update(CrowdList $crowdList, array $data, User $updatedBy): CrowdList
+    {
+        $oldValues = $crowdList->only(array_keys($data));
+
+        $crowdList->update($data);
+
+        activity('crowd_list')
+            ->causedBy($updatedBy)
+            ->performedOn($crowdList)
+            ->withProperties([
+                'old' => $oldValues,
+                'new' => $crowdList->only(array_keys($data)),
+            ])
+            ->log('crowd_list.updated');
+
+        return $crowdList->fresh();
+    }
+
+    public function delete(CrowdList $crowdList, User $deletedBy): void
+    {
+        activity('crowd_list')
+            ->causedBy($deletedBy)
+            ->performedOn($crowdList)
+            ->withProperties(['attributes' => $crowdList->only($crowdList->getFillable())])
+            ->log('crowd_list.deleted');
+
+        $crowdList->delete();
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    public function addPerson(CrowdList $crowdList, Person $person, User $addedBy): void
+    {
+        if ($crowdList->persons()->where('person_id', $person->id)->exists()) {
+            throw ValidationException::withMessages([
+                'person_id' => ['This person is already on this crowd list.'],
+            ]);
+        }
+
+        if ($crowdList->max_persons !== null) {
+            $currentCount = $crowdList->persons()->count();
+
+            if ($currentCount >= $crowdList->max_persons) {
+                throw ValidationException::withMessages([
+                    'person_id' => ['This crowd list has reached its maximum capacity of ' . $crowdList->max_persons . ' persons.'],
+                ]);
+            }
+        }
+
+        $crowdList->persons()->attach($person->id, [
+            'added_at' => now(),
+            'added_by_user_id' => $addedBy->id,
+        ]);
+
+        $wasAutoApproved = false;
+
+        if ($crowdList->auto_approve && $person->status !== 'approved') {
+            $person->update(['status' => 'approved']);
+            $wasAutoApproved = true;
+        }
+
+        activity('crowd_list')
+            ->causedBy($addedBy)
+            ->performedOn($crowdList)
+            ->withProperties([
+                'person_id' => $person->id,
+                'person_name' => $person->name,
+                'auto_approved' => $wasAutoApproved,
+            ])
+            ->log('crowd_list.person_added');
+    }
+
+    public function removePerson(CrowdList $crowdList, Person $person, User $removedBy): void
+    {
+        $crowdList->persons()->detach($person->id);
+
+        activity('crowd_list')
+            ->causedBy($removedBy)
+            ->performedOn($crowdList)
+            ->withProperties([
+                'person_id' => $person->id,
+                'person_name' => $person->name,
+            ])
+            ->log('crowd_list.person_removed');
+    }
+}
diff --git a/api/database/factories/CrowdListFactory.php b/api/database/factories/CrowdListFactory.php
new file mode 100644
index 00000000..099d88cc
--- /dev/null
+++ b/api/database/factories/CrowdListFactory.php
@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Factories;
+
+use App\Enums\CrowdListType;
+use App\Models\Company;
+use App\Models\CrowdList;
+use App\Models\CrowdType;
+use App\Models\Event;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/** @extends Factory<CrowdList> */
+final class CrowdListFactory extends Factory
+{
+    private const INTERNAL_NAMES = [
+        'VIP Gastenlijst',
+        'Backstage Crew',
+        'Barpersoneel',
+        'Opbouw Team',
+        'Afbouw Team',
+        'Vrijwilligers Hoofdpodium',
+        'Nachtploeg',
+        'EHBO Team',
+        'Parkeerteam',
+        'Kassa Medewerkers',
+    ];
+
+    private const EXTERNAL_NAMES = [
+        'Catering Medewerkers',
+        'Beveiligingspersoneel',
+        'Technische Crew',
+        'Schoonmaakploeg',
+        'Leveranciers Personeel',
+    ];
+
+    /** @return array<string, mixed> */
+    public function definition(): array
+    {
+        return [
+            'event_id' => Event::factory(),
+            'crowd_type_id' => CrowdType::factory(),
+            'name' => fake()->randomElement(self::INTERNAL_NAMES),
+            'type' => CrowdListType::INTERNAL,
+            'recipient_company_id' => null,
+            'auto_approve' => false,
+            'max_persons' => null,
+        ];
+    }
+
+    public function external(): static
+    {
+        return $this->state(fn () => [
+            'name' => fake()->randomElement(self::EXTERNAL_NAMES),
+            'type' => CrowdListType::EXTERNAL,
+            'recipient_company_id' => Company::factory(),
+        ]);
+    }
+
+    public function withAutoApprove(): static
+    {
+        return $this->state(fn () => [
+            'auto_approve' => true,
+        ]);
+    }
+
+    public function withMaxPersons(int $max): static
+    {
+        return $this->state(fn () => [
+            'max_persons' => $max,
+        ]);
+    }
+}
diff --git a/api/tests/Feature/CrowdList/CrowdListTest.php b/api/tests/Feature/CrowdList/CrowdListTest.php
new file mode 100644
index 00000000..1641a0c5
--- /dev/null
+++ b/api/tests/Feature/CrowdList/CrowdListTest.php
@@ -0,0 +1,480 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\CrowdList;
+
+use App\Models\Company;
+use App\Models\CrowdList;
+use App\Models\CrowdType;
+use App\Models\Event;
+use App\Models\Organisation;
+use App\Models\Person;
+use App\Models\User;
+use Database\Seeders\RoleSeeder;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Laravel\Sanctum\Sanctum;
+use Tests\TestCase;
+
+class CrowdListTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private User $orgAdmin;
+    private User $outsider;
+    private Organisation $organisation;
+    private Organisation $otherOrganisation;
+    private Event $event;
+    private Event $otherEvent;
+    private CrowdType $crowdType;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->seed(RoleSeeder::class);
+
+        $this->organisation = Organisation::factory()->create();
+        $this->otherOrganisation = Organisation::factory()->create();
+
+        $this->orgAdmin = User::factory()->create();
+        $this->organisation->users()->attach($this->orgAdmin, ['role' => 'org_admin']);
+
+        $this->outsider = User::factory()->create();
+        $this->otherOrganisation->users()->attach($this->outsider, ['role' => 'org_admin']);
+
+        $this->event = Event::factory()->create(['organisation_id' => $this->organisation->id]);
+        $this->otherEvent = Event::factory()->create(['organisation_id' => $this->otherOrganisation->id]);
+
+        $this->crowdType = CrowdType::factory()->systemType('VOLUNTEER')->create([
+            'organisation_id' => $this->organisation->id,
+        ]);
+    }
+
+    // ---- CRUD Tests ----
+
+    public function test_can_list_crowd_lists_for_event(): void
+    {
+        CrowdList::factory()->count(3)->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        // Add persons to one list to verify persons_count
+        $list = $this->event->crowdLists()->first();
+        $person = Person::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+        $list->persons()->attach($person->id, [
+            'added_at' => now(),
+            'added_by_user_id' => $this->orgAdmin->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->getJson("/api/v1/events/{$this->event->id}/crowd-lists");
+
+        $response->assertOk();
+        $this->assertCount(3, $response->json('data'));
+
+        // Verify persons_count is present
+        $listData = collect($response->json('data'))->firstWhere('id', $list->id);
+        $this->assertEquals(1, $listData['persons_count']);
+    }
+
+    public function test_can_create_internal_crowd_list(): void
+    {
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson("/api/v1/events/{$this->event->id}/crowd-lists", [
+            'crowd_type_id' => $this->crowdType->id,
+            'name' => 'VIP Gastenlijst',
+            'type' => 'internal',
+            'auto_approve' => true,
+            'max_persons' => 50,
+        ]);
+
+        $response->assertCreated();
+        $this->assertEquals('VIP Gastenlijst', $response->json('data.name'));
+        $this->assertEquals('internal', $response->json('data.type'));
+        $this->assertNull($response->json('data.recipient_company_id'));
+        $this->assertTrue($response->json('data.auto_approve'));
+        $this->assertEquals(50, $response->json('data.max_persons'));
+
+        $this->assertDatabaseHas('crowd_lists', [
+            'event_id' => $this->event->id,
+            'name' => 'VIP Gastenlijst',
+            'type' => 'internal',
+        ]);
+    }
+
+    public function test_can_create_external_crowd_list_with_company(): void
+    {
+        $company = Company::factory()->create([
+            'organisation_id' => $this->organisation->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson("/api/v1/events/{$this->event->id}/crowd-lists", [
+            'crowd_type_id' => $this->crowdType->id,
+            'name' => 'Catering Medewerkers',
+            'type' => 'external',
+            'recipient_company_id' => $company->id,
+        ]);
+
+        $response->assertCreated();
+        $this->assertEquals('external', $response->json('data.type'));
+        $this->assertEquals($company->id, $response->json('data.recipient_company_id'));
+    }
+
+    public function test_store_validates_invalid_type(): void
+    {
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson("/api/v1/events/{$this->event->id}/crowd-lists", [
+            'crowd_type_id' => $this->crowdType->id,
+            'name' => 'Test List',
+            'type' => 'invalid_type',
+        ]);
+
+        $response->assertUnprocessable()
+            ->assertJsonValidationErrors(['type']);
+    }
+
+    public function test_can_update_crowd_list(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+            'name' => 'Oude Naam',
+            'auto_approve' => false,
+            'max_persons' => null,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->putJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}", [
+            'name' => 'Nieuwe Naam',
+            'auto_approve' => true,
+            'max_persons' => 25,
+        ]);
+
+        $response->assertOk();
+        $this->assertEquals('Nieuwe Naam', $response->json('data.name'));
+        $this->assertTrue($response->json('data.auto_approve'));
+        $this->assertEquals(25, $response->json('data.max_persons'));
+    }
+
+    public function test_can_delete_crowd_list(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->deleteJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}");
+
+        $response->assertNoContent();
+        $this->assertDatabaseMissing('crowd_lists', ['id' => $crowdList->id]);
+    }
+
+    // ---- Person Management Tests ----
+
+    public function test_can_add_person_to_crowd_list(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+        $person = Person::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}/persons", [
+            'person_id' => $person->id,
+        ]);
+
+        $response->assertOk();
+
+        $this->assertDatabaseHas('crowd_list_persons', [
+            'crowd_list_id' => $crowdList->id,
+            'person_id' => $person->id,
+            'added_by_user_id' => $this->orgAdmin->id,
+        ]);
+    }
+
+    public function test_cannot_add_duplicate_person_to_crowd_list(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+        $person = Person::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        $crowdList->persons()->attach($person->id, [
+            'added_at' => now(),
+            'added_by_user_id' => $this->orgAdmin->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}/persons", [
+            'person_id' => $person->id,
+        ]);
+
+        $response->assertUnprocessable()
+            ->assertJsonValidationErrors(['person_id']);
+    }
+
+    public function test_cannot_add_person_beyond_max_persons(): void
+    {
+        $crowdList = CrowdList::factory()->withMaxPersons(2)->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        $persons = Person::factory()->count(3)->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        // Add two persons (fill the list)
+        foreach ($persons->take(2) as $person) {
+            $crowdList->persons()->attach($person->id, [
+                'added_at' => now(),
+                'added_by_user_id' => $this->orgAdmin->id,
+            ]);
+        }
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        // Try to add 3rd person
+        $response = $this->postJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}/persons", [
+            'person_id' => $persons->last()->id,
+        ]);
+
+        $response->assertUnprocessable()
+            ->assertJsonValidationErrors(['person_id']);
+    }
+
+    public function test_can_add_person_when_max_persons_is_null(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+            'max_persons' => null,
+        ]);
+
+        $persons = Person::factory()->count(5)->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        // Add all 5 persons — no limit
+        foreach ($persons as $person) {
+            $response = $this->postJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}/persons", [
+                'person_id' => $person->id,
+            ]);
+            $response->assertOk();
+        }
+
+        $this->assertEquals(5, $crowdList->persons()->count());
+    }
+
+    public function test_auto_approve_sets_person_status_to_approved(): void
+    {
+        $crowdList = CrowdList::factory()->withAutoApprove()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+        $person = Person::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+            'status' => 'pending',
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}/persons", [
+            'person_id' => $person->id,
+        ]);
+
+        $response->assertOk();
+
+        $this->assertDatabaseHas('persons', [
+            'id' => $person->id,
+            'status' => 'approved',
+        ]);
+    }
+
+    public function test_can_remove_person_from_crowd_list(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+        $person = Person::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        $crowdList->persons()->attach($person->id, [
+            'added_at' => now(),
+            'added_by_user_id' => $this->orgAdmin->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->deleteJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}/persons/{$person->id}");
+
+        $response->assertNoContent();
+
+        $this->assertDatabaseMissing('crowd_list_persons', [
+            'crowd_list_id' => $crowdList->id,
+            'person_id' => $person->id,
+        ]);
+
+        // Person still exists
+        $this->assertDatabaseHas('persons', ['id' => $person->id]);
+    }
+
+    public function test_crowd_list_resource_includes_persons_count(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        $persons = Person::factory()->count(3)->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        foreach ($persons as $person) {
+            $crowdList->persons()->attach($person->id, [
+                'added_at' => now(),
+                'added_by_user_id' => $this->orgAdmin->id,
+            ]);
+        }
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->getJson("/api/v1/events/{$this->event->id}/crowd-lists");
+
+        $response->assertOk();
+        $listData = collect($response->json('data'))->firstWhere('id', $crowdList->id);
+        $this->assertEquals(3, $listData['persons_count']);
+    }
+
+    // ---- Authorization Tests ----
+
+    public function test_cross_org_cannot_access_crowd_lists(): void
+    {
+        Sanctum::actingAs($this->outsider);
+
+        $response = $this->getJson("/api/v1/events/{$this->event->id}/crowd-lists");
+
+        $response->assertForbidden();
+    }
+
+    public function test_unauthenticated_cannot_access_crowd_lists(): void
+    {
+        $response = $this->getJson("/api/v1/events/{$this->event->id}/crowd-lists");
+
+        $response->assertUnauthorized();
+    }
+
+    public function test_cross_event_cannot_access_crowd_list(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        // Create a second event in the same org so the user has access to it
+        $eventB = Event::factory()->create(['organisation_id' => $this->organisation->id]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        // Try to update a list from event A via event B's URL
+        $response = $this->putJson("/api/v1/events/{$eventB->id}/crowd-lists/{$crowdList->id}", [
+            'name' => 'Hacked',
+        ]);
+
+        $response->assertForbidden();
+    }
+
+    // ---- Edge Case Tests ----
+
+    public function test_deleting_crowd_list_does_not_delete_persons(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+        $person = Person::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        $crowdList->persons()->attach($person->id, [
+            'added_at' => now(),
+            'added_by_user_id' => $this->orgAdmin->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $this->deleteJson("/api/v1/events/{$this->event->id}/crowd-lists/{$crowdList->id}")
+            ->assertNoContent();
+
+        // Pivot removed (cascade)
+        $this->assertDatabaseMissing('crowd_list_persons', [
+            'crowd_list_id' => $crowdList->id,
+        ]);
+
+        // Person still exists
+        $this->assertDatabaseHas('persons', ['id' => $person->id]);
+    }
+
+    public function test_persons_count_reflects_current_state(): void
+    {
+        $crowdList = CrowdList::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        $persons = Person::factory()->count(3)->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+
+        foreach ($persons as $person) {
+            $crowdList->persons()->attach($person->id, [
+                'added_at' => now(),
+                'added_by_user_id' => $this->orgAdmin->id,
+            ]);
+        }
+
+        // Remove one
+        $crowdList->persons()->detach($persons->first()->id);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->getJson("/api/v1/events/{$this->event->id}/crowd-lists");
+
+        $response->assertOk();
+        $listData = collect($response->json('data'))->firstWhere('id', $crowdList->id);
+        $this->assertEquals(2, $listData['persons_count']);
+    }
+}
diff --git a/dev-docs/API.md b/dev-docs/API.md
index 106d4a79..0c7863a2 100644
--- a/dev-docs/API.md
+++ b/dev-docs/API.md
@@ -163,12 +163,56 @@ Response: `{ "confirmed": 2, "errors": [{ "match_id": "ulid3", "error": "User al
 
 ## Crowd Lists
 
-- `GET /events/{event}/crowd-lists`
-- `POST /events/{event}/crowd-lists`
-- `PUT /events/{event}/crowd-lists/{list}`
-- `DELETE /events/{event}/crowd-lists/{list}`
-- `POST /events/{event}/crowd-lists/{list}/persons`
-- `DELETE /events/{event}/crowd-lists/{list}/persons/{person}`
+- `GET /events/{event}/crowd-lists` — list all crowd lists for event (includes `persons_count`)
+- `POST /events/{event}/crowd-lists` — create crowd list
+- `PUT /events/{event}/crowd-lists/{list}` — update crowd list
+- `DELETE /events/{event}/crowd-lists/{list}` — delete crowd list
+- `POST /events/{event}/crowd-lists/{list}/persons` — add person to list
+- `DELETE /events/{event}/crowd-lists/{list}/persons/{person}` — remove person from list
+
+### Create/Update Body
+
+```json
+{
+  "crowd_type_id": "01JXYZ...",
+  "name": "VIP Gastenlijst",
+  "type": "internal|external",
+  "recipient_company_id": "01JXYZ... (nullable, for external lists)",
+  "auto_approve": false,
+  "max_persons": 50
+}
+```
+
+### Add Person Body
+
+```json
+{
+  "person_id": "01JXYZ..."
+}
+```
+
+**Business rules:**
+- `max_persons`: when set, adding a person beyond the limit returns 422
+- `auto_approve`: when true, adding a person with status `pending` automatically sets their status to `approved`
+- Duplicate person on same list returns 422
+
+### CrowdListResource
+
+```json
+{
+  "id": "01JXYZ...",
+  "event_id": "01JXYZ...",
+  "crowd_type_id": "01JXYZ...",
+  "name": "VIP Gastenlijst",
+  "type": "internal",
+  "recipient_company_id": null,
+  "auto_approve": false,
+  "max_persons": 50,
+  "is_full": false,
+  "created_at": "2026-04-10T12:00:00+00:00",
+  "persons_count": 12
+}
+```
 
 ## Locations