diff --git a/EnvelopeGenerator.Tests/Application/DeleteEnvelopeCommandTests.cs b/EnvelopeGenerator.Tests/Application/DeleteEnvelopeCommandTests.cs
new file mode 100644
index 00000000..59843417
--- /dev/null
+++ b/EnvelopeGenerator.Tests/Application/DeleteEnvelopeCommandTests.cs
@@ -0,0 +1,109 @@
+using DigitalData.Core.Exceptions;
+using DigitalData.EmailProfilerDispatcher.Abstraction.Entities;
+using EnvelopeGenerator.Application.Envelopes.Commands;
+using EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.Domain.Entities;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace EnvelopeGenerator.Tests.Application;
+
+[TestFixture]
+public class DeleteEnvelopeCommandTests : TestBase
+{
+    protected override void ConfigureServices(IServiceCollection services)
+    {
+    }
+
+    [Test]
+    public async Task DeleteEnvelope_DraftEnvelope_ShouldSetDeleted_CreateHistory_AndQueueDeletionEmail()
+    {
+        CancellationToken cancel = default;
+        var reason = "Invalid receiver data";
+
+        var envelope = this.CreateEnvelope(User.Id);
+        envelope.Status = EnvelopeStatus.EnvelopeCreated;
+        envelope = await GetRepository<Envelope>().CreateAsync(envelope, cancel);
+
+        var createReceiverCmd = this.CreateReceiverCommand();
+        (var receiver, _) = await Mediator.Send(createReceiverCmd, cancel);
+
+        var envReceiver = this.CreateEnvelopeReceiver(envelope.Id, receiver.Id);
+        await GetRepository<EnvelopeReceiver>().CreateAsync(envReceiver, cancel);
+
+        var result = await Mediator.Send(new DeleteEnvelopeCommand
+        {
+            EnvelopeId = envelope.Id,
+            Reason = reason
+        }.WithAuth(User.Id), cancel);
+
+        Assert.That(result.EnvelopeId, Is.EqualTo(envelope.Id));
+        Assert.That(result.AppliedStatus, Is.EqualTo(EnvelopeStatus.EnvelopeDeleted));
+        Assert.That(result.IsNoOp, Is.False);
+
+        var histories = await GetRepository<History>().Query
+            .Where(h => h.EnvelopeId == envelope.Id && h.Status == EnvelopeStatus.EnvelopeDeleted)
+            .ToListAsync(cancel);
+        Assert.That(histories, Has.Count.EqualTo(1));
+        Assert.That(histories[0].Comment, Is.EqualTo(reason));
+
+        var emails = await GetRepository<EmailOut>().Query
+            .Where(e => e.WfId == (int)EnvelopeStatus.MessageDeletionSent && e.ReferenceId == receiver.Id)
+            .ToListAsync(cancel);
+        Assert.That(emails, Has.Count.EqualTo(1));
+        Assert.That(emails[0].EmailAddress, Is.EqualTo(receiver.EmailAddress));
+    }
+
+    [Test]
+    public async Task DeleteEnvelope_SentEnvelope_ShouldSetWithdrawn()
+    {
+        CancellationToken cancel = default;
+
+        var envelope = this.CreateEnvelope(User.Id);
+        envelope.Status = EnvelopeStatus.EnvelopeQueued;
+        envelope = await GetRepository<Envelope>().CreateAsync(envelope, cancel);
+
+        var result = await Mediator.Send(new DeleteEnvelopeCommand
+        {
+            EnvelopeId = envelope.Id,
+            Reason = "Sender requested cancellation"
+        }.WithAuth(User.Id), cancel);
+
+        Assert.That(result.AppliedStatus, Is.EqualTo(EnvelopeStatus.EnvelopeWithdrawn));
+
+        var histories = await GetRepository<History>().Query
+            .Where(h => h.EnvelopeId == envelope.Id && h.Status == EnvelopeStatus.EnvelopeWithdrawn)
+            .ToListAsync(cancel);
+        Assert.That(histories, Has.Count.EqualTo(1));
+    }
+
+    [Test]
+    public void DeleteEnvelope_MissingReason_ShouldThrowBadRequest()
+    {
+        Assert.ThrowsAsync<BadRequestException>(async () =>
+            await Mediator.Send(new DeleteEnvelopeCommand
+            {
+                EnvelopeId = 123,
+                Reason = "   "
+            }.WithAuth(User.Id)));
+    }
+
+    [Test]
+    public async Task DeleteEnvelope_WrongOwner_ShouldThrowForbidden()
+    {
+        CancellationToken cancel = default;
+
+        var envelope = this.CreateEnvelope(User.Id);
+        envelope = await GetRepository<Envelope>().CreateAsync(envelope, cancel);
+
+        var otherUserCmd = this.CreateUserCommand();
+        var otherUser = await GetRepository<DigitalData.UserManager.Domain.Entities.User>().CreateAsync(otherUserCmd, cancel);
+
+        Assert.ThrowsAsync<ForbiddenException>(async () =>
+            await Mediator.Send(new DeleteEnvelopeCommand
+            {
+                EnvelopeId = envelope.Id,
+                Reason = "Not allowed"
+            }.WithAuth(otherUser.Id), cancel));
+    }
+}
diff --git a/EnvelopeGenerator.Tests/Application/Fake.cs b/EnvelopeGenerator.Tests/Application/Fake.cs
index 9f424b70..ca15c07d 100644
--- a/EnvelopeGenerator.Tests/Application/Fake.cs
+++ b/EnvelopeGenerator.Tests/Application/Fake.cs
@@ -52,7 +52,7 @@ public class Fake
 
             services.AddEnvelopeGeneratorInfrastructureServices(opt =>
             {
-                opt.AddDbContext(dbCtxOpt => dbCtxOpt.UseInMemoryDatabase("EnvelopeGeneratorTestDb"));
+                opt.AddDbContext(dbCtxOpt => dbCtxOpt.UseInMemoryDatabase($"EnvelopeGeneratorTestDb_{Guid.NewGuid():N}"));
 
                 opt.AddDbTriggerParams(context.Configuration);
 
@@ -308,4 +308,4 @@ public static class Extensions
             .Select(_ => fake.CreateUserCommand())
             .ToList();
     #endregion
-}
\ No newline at end of file
+}
diff --git a/EnvelopeGenerator.Tests/Application/TestBase.cs b/EnvelopeGenerator.Tests/Application/TestBase.cs
index f5b362e6..d4a11c7a 100644
--- a/EnvelopeGenerator.Tests/Application/TestBase.cs
+++ b/EnvelopeGenerator.Tests/Application/TestBase.cs
@@ -38,7 +38,10 @@ public abstract class TestBase : Faker
 
         // Add seed email templates
         foreach (var temp in SeedEmailTemplates)
+        {
+            temp.LangCode ??= "de";
             await repo.CreateAsync(temp);
+        }
     }
 
     [TearDown]
@@ -140,4 +143,4 @@ public abstract class TestBase : Faker
             ChangedWhen = DateTime.Parse("2025-05-12 10:43:44.290")
         }
     };
-}
\ No newline at end of file
+}