diff --git a/src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/Dialogs/Commands/Create/CreateDialogCommandValidator.cs b/src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/Dialogs/Commands/Create/CreateDialogCommandValidator.cs
index ca76bf84f..b85799516 100644
--- a/src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/Dialogs/Commands/Create/CreateDialogCommandValidator.cs
+++ b/src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/Dialogs/Commands/Create/CreateDialogCommandValidator.cs
@@ -31,6 +31,20 @@ public CreateDialogCommandValidator(
             .IsValidUuidV7()
             .UuidV7TimestampIsInPast();
 
+        RuleFor(x => x.CreatedAt)
+            .IsInPast();
+
+        RuleFor(x => x.CreatedAt)
+            .NotEmpty()
+                .WithMessage($"{{PropertyName}} must not be empty when '{nameof(CreateDialogCommand.UpdatedAt)} is set.")
+                .When(x => x.UpdatedAt != default);
+
+        RuleFor(x => x.UpdatedAt)
+            .IsInPast()
+            .GreaterThanOrEqualTo(x => x.CreatedAt)
+                .WithMessage($"'{{PropertyName}}' must be greater than or equal to '{nameof(CreateDialogCommand.CreatedAt)}'.")
+                .When(x => x.CreatedAt != default && x.UpdatedAt != default);
+
         RuleFor(x => x.ServiceResource)
             .NotNull()
             .IsValidUri()
diff --git a/src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/Dialogs/Commands/Create/CreateDialogDto.cs b/src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/Dialogs/Commands/Create/CreateDialogDto.cs
index 0aaaf1312..036139396 100644
--- a/src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/Dialogs/Commands/Create/CreateDialogDto.cs
+++ b/src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/Dialogs/Commands/Create/CreateDialogDto.cs
@@ -95,7 +95,7 @@ public class CreateDialogDto
     /// If not supplied, the current date /time will be used.
     /// </summary>
     /// <example>2022-12-31T23:59:59Z</example>
-    public DateTimeOffset UpdatedAt { get; set; } // TODO: This does not work, as UpdatedAt is always overwritten
+    public DateTimeOffset UpdatedAt { get; set; }
 
     /// <summary>
     /// The aggregated status of the dialog.
diff --git a/src/Digdir.Library.Entity.Abstractions/Features/Aggregate/AggregateNode.cs b/src/Digdir.Library.Entity.Abstractions/Features/Aggregate/AggregateNode.cs
index 9c729f4f2..297dca3fc 100644
--- a/src/Digdir.Library.Entity.Abstractions/Features/Aggregate/AggregateNode.cs
+++ b/src/Digdir.Library.Entity.Abstractions/Features/Aggregate/AggregateNode.cs
@@ -1,4 +1,5 @@
 using System.Reflection;
+using Digdir.Library.Entity.Abstractions.Features.Updatable;
 
 namespace Digdir.Library.Entity.Abstractions.Features.Aggregate;
 
@@ -88,6 +89,34 @@ internal static AggregateNode Create(Type type, object entity, AggregateNodeStat
     /// Convenience method to check if the state of the node is <see cref="AggregateNodeState.Modified"/> and not by a child node.
     /// </summary>
     public bool IsDirectlyModified() => State is AggregateNodeState.Modified && !ModifiedByChild;
+
+    /// <summary>
+    /// Convenience method to check if the state of the node is <see cref="AggregateNodeState.Added"/>.
+    /// </summary>
+    public bool IsAdded() => State is AggregateNodeState.Added;
+
+    /// <summary>
+    /// Convenience method to check if the state of the node is <see cref="AggregateNodeState.Modified"/>.
+    /// </summary>
+    public bool IsModified() => State is AggregateNodeState.Modified;
+
+    /// <summary>
+    /// Convenience method to check if the state of the node is <see cref="AggregateNodeState.Restored"/>.
+    /// </summary>
+    public bool IsRestored() => State is AggregateNodeState.Restored;
+
+    /// <summary>
+    /// Convenience method to check if the state of the node is <see cref="AggregateNodeState.Deleted"/>.
+    /// </summary>
+    public bool IsDeleted() => State is AggregateNodeState.Deleted;
+
+    /// <summary>
+    /// Convenience method to check if the state of the node is <see cref="AggregateNodeState.Added"/>,
+    /// and that UpdatedAt is the default value.
+    /// </summary>
+    /// <param name="updatable"></param>
+    public bool IsAddedWithDefaultUpdatedAt(IUpdateableEntity updatable)
+        => IsAdded() && updatable.UpdatedAt == default;
 }
 
 /// <summary>
diff --git a/src/Digdir.Library.Entity.EntityFrameworkCore/Features/Aggregate/AggregateExtensions.cs b/src/Digdir.Library.Entity.EntityFrameworkCore/Features/Aggregate/AggregateExtensions.cs
index 6b3c38a78..3a6085906 100644
--- a/src/Digdir.Library.Entity.EntityFrameworkCore/Features/Aggregate/AggregateExtensions.cs
+++ b/src/Digdir.Library.Entity.EntityFrameworkCore/Features/Aggregate/AggregateExtensions.cs
@@ -24,29 +24,32 @@ internal static async Task HandleAggregateEntities(this ChangeTracker changeTrac
 
         foreach (var (_, aggregateNode) in aggregateNodeByEntry)
         {
-            if (aggregateNode.Entity is IAggregateCreatedHandler created && aggregateNode.State is AggregateNodeState.Added)
+            if (aggregateNode.Entity is IAggregateCreatedHandler created && aggregateNode.IsAdded())
             {
                 created.OnCreate(aggregateNode, utcNow);
             }
 
-            if (aggregateNode.Entity is IAggregateUpdatedHandler updated && aggregateNode.State is AggregateNodeState.Modified)
+            if (aggregateNode.Entity is IAggregateUpdatedHandler updated && aggregateNode.IsModified())
             {
                 updated.OnUpdate(aggregateNode, utcNow);
             }
 
-            if (aggregateNode.Entity is IAggregateDeletedHandler deleted && aggregateNode.State is AggregateNodeState.Deleted)
+            if (aggregateNode.Entity is IAggregateDeletedHandler deleted && aggregateNode.IsDeleted())
             {
                 deleted.OnDelete(aggregateNode, utcNow);
             }
 
-            if (aggregateNode.Entity is IAggregateRestoredHandler restored && aggregateNode.State is AggregateNodeState.Restored)
+            if (aggregateNode.Entity is IAggregateRestoredHandler restored && aggregateNode.IsRestored())
             {
                 restored.OnRestore(aggregateNode, utcNow);
             }
 
             if (aggregateNode.Entity is IUpdateableEntity updatable)
             {
-                updatable.Update(utcNow);
+                if (aggregateNode.IsModified() || aggregateNode.IsAddedWithDefaultUpdatedAt(updatable))
+                {
+                    updatable.Update(utcNow);
+                }
             }
 
             if (aggregateNode.Entity is IVersionableEntity versionable)
diff --git a/tests/Digdir.Domain.Dialogporten.Application.Integration.Tests/Features/V1/ServiceOwner/Dialogs/Commands/CreateDialogTests.cs b/tests/Digdir.Domain.Dialogporten.Application.Integration.Tests/Features/V1/ServiceOwner/Dialogs/Commands/CreateDialogTests.cs
index 795c643cd..db17226ed 100644
--- a/tests/Digdir.Domain.Dialogporten.Application.Integration.Tests/Features/V1/ServiceOwner/Dialogs/Commands/CreateDialogTests.cs
+++ b/tests/Digdir.Domain.Dialogporten.Application.Integration.Tests/Features/V1/ServiceOwner/Dialogs/Commands/CreateDialogTests.cs
@@ -1,4 +1,5 @@
-using Digdir.Domain.Dialogporten.Application.Integration.Tests.Common;
+using Digdir.Domain.Dialogporten.Application.Features.V1.ServiceOwner.Dialogs.Queries.Get;
+using Digdir.Domain.Dialogporten.Application.Integration.Tests.Common;
 using Digdir.Tool.Dialogporten.GenerateFakeData;
 using FluentAssertions;
 using static Digdir.Domain.Dialogporten.Application.Integration.Tests.UuiDv7Utils;
@@ -108,5 +109,98 @@ public async Task Create_CreateDialog_WhenDialogIsComplex()
         success.Value.Should().Be(expectedDialogId);
     }
 
-    // TODO: Add tests
+    [Fact]
+    public async Task Can_Create_Dialog_With_UpdatedAt_Supplied()
+    {
+        // Arrange
+        var dialogId = GenerateBigEndianUuidV7();
+        var createdAt = DateTimeOffset.UtcNow.AddYears(-20);
+        var updatedAt = DateTimeOffset.UtcNow.AddYears(-15);
+        var createDialogCommand = DialogGenerator.GenerateFakeDialog(id: dialogId, updatedAt: updatedAt, createdAt: createdAt);
+
+        // Act
+        var createDialogResult = await Application.Send(createDialogCommand);
+        var getDialogQuery = new GetDialogQuery
+        {
+            DialogId = dialogId
+        };
+
+        var getDialogResponse = await Application.Send(getDialogQuery);
+
+        // Assert
+        createDialogResult.TryPickT0(out var dialogCreatedSuccess, out _).Should().BeTrue();
+        dialogCreatedSuccess.Value.Should().Be(dialogId);
+
+        getDialogQuery.Should().NotBeNull();
+        getDialogResponse.TryPickT0(out var dialog, out _).Should().BeTrue();
+        dialog.Should().NotBeNull();
+        dialog.CreatedAt.Should().BeCloseTo(createdAt, precision: TimeSpan.FromMicroseconds(10));
+        dialog.UpdatedAt.Should().BeCloseTo(updatedAt, precision: TimeSpan.FromMicroseconds(10));
+    }
+
+    [Fact]
+    public async Task Cant_Create_Dialog_With_UpdatedAt_Supplied_Without_CreatedAt_Supplied()
+    {
+        // Arrange
+        var updatedAt = DateTimeOffset.UtcNow.AddYears(-15);
+        var createDialogCommand = DialogGenerator.GenerateFakeDialog(updatedAt: updatedAt);
+
+        // Act
+        var response = await Application.Send(createDialogCommand);
+
+        // Assert
+        response.TryPickT2(out var validationError, out _).Should().BeTrue();
+        validationError.Should().NotBeNull();
+        validationError.Errors.Should().Contain(e => e.ErrorMessage.Contains(nameof(createDialogCommand.UpdatedAt)));
+    }
+
+    [Fact]
+    public async Task Cant_Create_Dialog_With_UpdatedAt_Date_Earlier_Than_CreatedAt_Date()
+    {
+        // Arrange
+        var createdAt = DateTimeOffset.UtcNow.AddYears(-10);
+        var updatedAt = DateTimeOffset.UtcNow.AddYears(-15);
+        var createDialogCommand = DialogGenerator.GenerateFakeDialog(updatedAt: updatedAt, createdAt: createdAt);
+
+        // Act
+        var response = await Application.Send(createDialogCommand);
+
+        // Assert
+        response.TryPickT2(out var validationError, out _).Should().BeTrue();
+        validationError.Should().NotBeNull();
+        validationError.Errors.Should().Contain(e => e.ErrorMessage.Contains(nameof(createDialogCommand.CreatedAt)));
+    }
+
+    [Fact]
+    public async Task Cant_Create_Dialog_With_UpdatedAt_Or_CreatedAt_In_The_Future()
+    {
+        // Arrange
+        var aYearFromNow = DateTimeOffset.UtcNow.AddYears(1);
+        var createDialogCommand = DialogGenerator
+            .GenerateFakeDialog(updatedAt: aYearFromNow, createdAt: aYearFromNow);
+
+        // Act
+        var response = await Application.Send(createDialogCommand);
+
+        //
+        response.TryPickT2(out var validationError, out _).Should().BeTrue();
+        validationError.Should().NotBeNull();
+        validationError.Errors.Should().Contain(e => e.ErrorMessage.Contains("in the past"));
+    }
+
+    [Fact]
+    public async Task Can_Create_Dialog_With_UpdatedAt_And_CreatedAt_Being_Equal()
+    {
+        // Arrange
+        var aYearAgo = DateTimeOffset.UtcNow.AddYears(-1);
+        var createDialogCommand = DialogGenerator
+            .GenerateFakeDialog(updatedAt: aYearAgo, createdAt: aYearAgo);
+
+        // Act
+        var response = await Application.Send(createDialogCommand);
+
+        // Assert
+        response.TryPickT0(out var success, out _).Should().BeTrue();
+        success.Should().NotBeNull();
+    }
 }