diff --git a/app/Form/Actions/RegisterAction.php b/app/Form/Actions/RegisterAction.php
index f4f513c9..854ed7fd 100644
--- a/app/Form/Actions/RegisterAction.php
+++ b/app/Form/Actions/RegisterAction.php
@@ -22,11 +22,11 @@ class RegisterAction
         $memberQuery = FieldCollection::fromRequest($form, $input)
             ->withNamiType()
             ->reduce(fn ($query, $field) => $field->namiType->performQuery($query, $field->value), (new Member())->newQuery());
-        $mglnr = $form->getFields()->withNamiType()->count() && $memberQuery->count() === 1 ? $memberQuery->first()->mitgliedsnr : null;
+        $member = $form->getFields()->withNamiType()->count() && $memberQuery->count() === 1 ? $memberQuery->first() : null;
 
         $participant = $form->participants()->create([
             'data' => $input,
-            'mitgliedsnr' => $mglnr,
+            'member_id' => $member?->id,
         ]);
 
         $form->getFields()->each(fn ($field) => $field->afterRegistration($form, $participant, $input));
diff --git a/app/Form/Fields/NamiField.php b/app/Form/Fields/NamiField.php
index bce954bd..443c51a8 100644
--- a/app/Form/Fields/NamiField.php
+++ b/app/Form/Fields/NamiField.php
@@ -116,7 +116,7 @@ class NamiField extends Field
             }
 
             $data[$this->key] = [];
-            $form->participants()->create(['data' => $data, 'mitgliedsnr' => $memberData['id'], 'parent_id' => $participant->id]);
+            $form->participants()->create(['data' => $data, 'member_id' => $member?->id, 'parent_id' => $participant->id]);
         }
     }
 
diff --git a/database/migrations/2024_07_02_155058_update_member_participants_column.php b/database/migrations/2024_07_02_155058_update_member_participants_column.php
new file mode 100644
index 00000000..5c1a1d3e
--- /dev/null
+++ b/database/migrations/2024_07_02_155058_update_member_participants_column.php
@@ -0,0 +1,46 @@
+<?php
+
+use App\Form\Models\Participant;
+use App\Member\Member;
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('participants', function (Blueprint $table) {
+            $table->renameColumn('mitgliedsnr', 'member_id')->nullable();
+        });
+
+        Schema::table('participants', function (Blueprint $table) {
+            $table->unsignedBigInteger('member_id')->nullable(true)->change();
+        });
+
+        foreach (Participant::whereNotNull('member_id')->get() as $p) {
+            $p->update(['member_id' => Member::firstWhere('mitgliedsnr', $p->member_id)?->id]);
+        }
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('participants', function (Blueprint $table) {
+            $table->string('member_id')->nullable(true)->change();
+        });
+
+        Schema::table('participants', function (Blueprint $table) {
+            $table->renameColumn('member_id', 'mitgliedsnr');
+        });
+    }
+};
diff --git a/tests/Feature/Form/FormRegisterActionTest.php b/tests/Feature/Form/FormRegisterActionTest.php
index ce0583eb..9af378ac 100644
--- a/tests/Feature/Form/FormRegisterActionTest.php
+++ b/tests/Feature/Form/FormRegisterActionTest.php
@@ -394,7 +394,7 @@ class FormRegisterActionTest extends FormTestCase
     public function testItSetsMitgliedsnrForMainMember(): void
     {
         $this->login()->loginNami();
-        $this->createMember(['mitgliedsnr' => '9966', 'email' => 'max@muster.de', 'firstname' => 'Max', 'lastname' => 'Muster']);
+        $member = $this->createMember(['mitgliedsnr' => '9966', 'email' => 'max@muster.de', 'firstname' => 'Max', 'lastname' => 'Muster']);
         $form = Form::factory()->fields([
             $this->textField('email')->namiType(NamiType::EMAIL),
             $this->textField('firstname')->namiType(NamiType::FIRSTNAME),
@@ -403,7 +403,7 @@ class FormRegisterActionTest extends FormTestCase
             ->create();
 
         $this->register($form, ['email' => 'max@muster.de', 'firstname' => 'Max', 'lastname' => 'Muster'])->assertOk();
-        $this->assertEquals('9966', $form->participants->first()->mitgliedsnr);
+        $this->assertEquals($member->id, $form->participants->first()->member_id);
     }
 
     public function testItDoesntSetMitgliedsnrWhenFieldDoesntHaveType(): void
@@ -416,7 +416,7 @@ class FormRegisterActionTest extends FormTestCase
             ->create();
 
         $this->register($form, ['email' => 'max@muster.de'])->assertOk();
-        $this->assertNull($form->participants->first()->mitgliedsnr);
+        $this->assertNull($form->participants->first()->member_id);
     }
 
     public function testItDoesntSyncMembersWhenTwoMembersMatch(): void
@@ -710,14 +710,14 @@ class FormRegisterActionTest extends FormTestCase
     public function testParticipantsHaveRelationToActualMember(): void
     {
         $this->login()->loginNami();
-        $this->createMember(['mitgliedsnr' => '5505']);
+        $member = $this->createMember(['mitgliedsnr' => '5505']);
         $form = Form::factory()->fields([
             $this->namiField('members'),
         ])
             ->create();
 
         $this->register($form, ['members' => [['id' => '5505']]])->assertOk();
-        $this->assertEquals('5505', $form->participants->get(1)->mitgliedsnr);
+        $this->assertEquals($member->id, $form->participants->get(1)->member_id);
     }
 
     public function testItSetsRegionIdAndGroupIdOfParentGroup(): void