diff --git a/src/Controllers/Storage/ProcessController.cs b/src/Controllers/Storage/ProcessController.cs
index 52d1b662..a778d500 100644
--- a/src/Controllers/Storage/ProcessController.cs
+++ b/src/Controllers/Storage/ProcessController.cs
@@ -21,6 +21,7 @@ public class ProcessController : ControllerBase
     {
         private readonly IInstanceRepository _instanceRepository;
         private readonly IInstanceEventRepository _instanceEventRepository;
+        private readonly IInstanceAndEventsRepository _instanceAndEventsRepository;
         private readonly string _storageBaseAndHost;
         private readonly IAuthorization _authorizationService;
         private readonly IInstanceEventService _instanceEventService;
@@ -30,18 +31,21 @@ public class ProcessController : ControllerBase
         /// </summary>
         /// <param name="instanceRepository">the instance repository handler</param>
         /// <param name="instanceEventRepository">the instance event repository service</param>
+        /// <param name="instanceAndEventsRepository">the instance and events repository</param>
         /// <param name="generalsettings">the general settings</param>
         /// <param name="authorizationService">the authorization service</param>
         /// <param name="instanceEventService">the instance event service</param>
         public ProcessController(
             IInstanceRepository instanceRepository,
             IInstanceEventRepository instanceEventRepository,
+            IInstanceAndEventsRepository instanceAndEventsRepository,
             IOptions<GeneralSettings> generalsettings,
             IAuthorization authorizationService,
             IInstanceEventService instanceEventService)
         {
             _instanceRepository = instanceRepository;
             _instanceEventRepository = instanceEventRepository;
+            _instanceAndEventsRepository = instanceAndEventsRepository;
             _storageBaseAndHost = $"{generalsettings.Value.Hostname}/storage/api/v1/";
             _authorizationService = authorizationService;
             _instanceEventService = instanceEventService;
@@ -63,72 +67,94 @@ public ProcessController(
         public async Task<ActionResult<Instance>> PutProcess(
             int instanceOwnerPartyId,
             Guid instanceGuid,
-            [FromBody] ProcessState processState
-        )
+            [FromBody] ProcessState processState)
         {
-            Instance existingInstance = await _instanceRepository.GetOne(
-                instanceOwnerPartyId,
-                instanceGuid
-            );
+            Instance existingInstance = await _instanceRepository.GetOne(instanceOwnerPartyId, instanceGuid);
 
             if (existingInstance is null)
             {
                 return NotFound();
             }
 
-            string taskId = null;
-            string altinnTaskType = existingInstance.Process?.CurrentTask?.AltinnTaskType;
+            var (action, taskId) = ActionMapping(processState, existingInstance);
 
-            if (processState?.CurrentTask?.FlowType == "AbandonCurrentMoveToNext")
-            {
-                altinnTaskType = "reject";
-            }
-            else if (
-                processState?.CurrentTask?.FlowType is not null
-                && processState.CurrentTask.FlowType != "CompleteCurrentMoveToNext"
-            )
+            bool authorized = await _authorizationService.AuthorizeInstanceAction(existingInstance, action, taskId);
+
+            if (!authorized)
             {
-                altinnTaskType = processState.CurrentTask.AltinnTaskType;
-                taskId = processState.CurrentTask.ElementId;
+                return Forbid();
             }
 
-            string action = altinnTaskType switch
+            UpdateInstance(existingInstance, processState, out _);
+
+            Instance updatedInstance = await _instanceRepository.Update(existingInstance);
+
+            if (processState?.CurrentTask?.AltinnTaskType == "signing")
             {
-                "data" or "feedback" => "write",
-                "payment" => "pay",
-                "confirmation" => "confirm",
-                "signing" => "sign",
-                _ => altinnTaskType,
-            };
+                await _instanceEventService.DispatchEvent(InstanceEventType.SentToSign, updatedInstance);
+            }
 
-            bool authorized = await _authorizationService.AuthorizeInstanceAction(existingInstance, action, taskId);
+            updatedInstance.SetPlatformSelfLinks(_storageBaseAndHost);
+            return Ok(updatedInstance);
+        }
+        
+        /// <summary>
+        /// Updates the process state of an instance.
+        /// </summary>
+        /// <param name="instanceOwnerPartyId">The party id of the instance owner.</param>
+        /// <param name="instanceGuid">The id of the instance that should have its process updated.</param>
+        /// <param name="processStateUpdate">The new process state of the instance (including instance events).</param>
+        /// <returns></returns>
+        [Authorize]
+        [HttpPut("instanceandevents")]
+        [Consumes("application/json")]
+        [ProducesResponseType(StatusCodes.Status200OK)]
+        [ProducesResponseType(StatusCodes.Status404NotFound)]
+        [ProducesResponseType(StatusCodes.Status400BadRequest)]
+        [Produces("application/json")]
+        public async Task<ActionResult<Instance>> PutInstanceAndEvents(
+            int instanceOwnerPartyId,
+            Guid instanceGuid,
+            [FromBody] ProcessStateUpdate processStateUpdate)
+        {
+            Instance existingInstance = await _instanceRepository.GetOne(instanceOwnerPartyId, instanceGuid);
 
-            if (!authorized)
+            if (existingInstance is null)
             {
-                return Forbid();
+                return NotFound();
             }
 
-            // Archiving instance if process was ended
-            if (existingInstance.Process?.Ended is null && processState?.Ended is not null)
+            foreach (var instanceEvent in processStateUpdate.Events ?? [])
             {
-                existingInstance.Status ??= new InstanceStatus();
-                existingInstance.Status.IsArchived = true;
-                existingInstance.Status.Archived = processState.Ended;
+                if (string.IsNullOrWhiteSpace(instanceEvent.InstanceId))
+                {
+                    return BadRequest("Missing parameter values: instance event must exist and instanceId must be set");
+                }
+
+                instanceEvent.Created = instanceEvent.Created?.ToUniversalTime() ?? DateTime.UtcNow;
             }
 
-            existingInstance.Process = processState;
-            existingInstance.LastChangedBy = User.GetUserOrOrgId();
-            existingInstance.LastChanged = DateTime.UtcNow;
+            ProcessState processState = processStateUpdate.State;
 
-            Instance updatedInstance;
+            var (action, taskId) = ActionMapping(processState, existingInstance);
 
-            updatedInstance = await _instanceRepository.Update(existingInstance);
+            bool authorized = await _authorizationService.AuthorizeInstanceAction(existingInstance, action, taskId);
 
+            if (!authorized)
+            {
+                return Forbid();
+            }
+
+            processStateUpdate.Events ??= [];
+            UpdateInstance(existingInstance, processState, out var updateProperties);
             if (processState?.CurrentTask?.AltinnTaskType == "signing")
             {
-                await _instanceEventService.DispatchEvent(InstanceEventType.SentToSign, updatedInstance);
+                InstanceEvent instanceEvent = _instanceEventService.BuildInstanceEvent(InstanceEventType.SentToSign, existingInstance);
+                processStateUpdate.Events.Add(instanceEvent);
             }
 
+            Instance updatedInstance = await _instanceAndEventsRepository.Update(existingInstance, updateProperties, processStateUpdate.Events);
+
             updatedInstance.SetPlatformSelfLinks(_storageBaseAndHost);
             return Ok(updatedInstance);
         }
@@ -156,5 +182,56 @@ public async Task<ActionResult<ProcessHistoryList>> GetProcessHistory(
 
             return Ok(processHistoryList);
         }
+
+        private void UpdateInstance(Instance existingInstance, ProcessState processState, out List<string> updateProperties)
+        {
+            // Archiving instance if process was ended
+            updateProperties = [
+                nameof(existingInstance.Process),
+                nameof(existingInstance.LastChanged),
+                nameof(existingInstance.LastChangedBy)
+            ];
+            if (existingInstance.Process?.Ended is null && processState?.Ended is not null)
+            {
+                existingInstance.Status ??= new InstanceStatus();
+                existingInstance.Status.IsArchived = true;
+                existingInstance.Status.Archived = processState.Ended;
+                updateProperties.Add(nameof(existingInstance.Status));
+                updateProperties.Add(nameof(existingInstance.Status.IsArchived));
+                updateProperties.Add(nameof(existingInstance.Status.Archived));
+            }
+
+            existingInstance.Process = processState;
+            existingInstance.LastChangedBy = User.GetUserOrOrgId();
+            existingInstance.LastChanged = DateTime.UtcNow;
+        }
+
+        private (string Action, string TaskId) ActionMapping(ProcessState processState, Instance existingInstance)
+        {
+            string taskId = null;
+            string altinnTaskType = existingInstance.Process?.CurrentTask?.AltinnTaskType;
+
+            if (processState?.CurrentTask?.FlowType == "AbandonCurrentMoveToNext")
+            {
+                altinnTaskType = "reject";
+            }
+            else if (processState?.CurrentTask?.FlowType is not null
+                && processState.CurrentTask.FlowType != "CompleteCurrentMoveToNext")
+            {
+                altinnTaskType = processState.CurrentTask.AltinnTaskType;
+                taskId = processState.CurrentTask.ElementId;
+            }
+
+            string action = altinnTaskType switch
+            {
+                "data" or "feedback" => "write",
+                "payment" => "pay",
+                "confirmation" => "confirm",
+                "signing" => "sign",
+                _ => altinnTaskType,
+            };
+
+            return (action, taskId);
+        }
     }
 }
diff --git a/src/LocalTest.csproj b/src/LocalTest.csproj
index 68052349..a3949524 100644
--- a/src/LocalTest.csproj
+++ b/src/LocalTest.csproj
@@ -13,7 +13,7 @@
     <PackageReference Include="Altinn.Authorization.ABAC" Version="0.0.8" />
     <PackageReference Include="Altinn.Common.PEP" Version="3.0.0" />
     <PackageReference Include="Altinn.Platform.Models" Version="1.6.1" />
-    <PackageReference Include="Altinn.Platform.Storage.Interface" Version="3.30.0" />
+    <PackageReference Include="Altinn.Platform.Storage.Interface" Version="4.0.4" />
     <PackageReference Include="AutoMapper.Extensions.Microsoft.DependencyInjection" Version="12.0.1" />
     <PackageReference Include="FluentValidation" Version="11.10.0" />
     <PackageReference Include="JWTCookieAuthentication" Version="2.4.2" />
diff --git a/src/Services/Storage/Implementation/InstanceAndEventsRepository.cs b/src/Services/Storage/Implementation/InstanceAndEventsRepository.cs
new file mode 100644
index 00000000..766b3d74
--- /dev/null
+++ b/src/Services/Storage/Implementation/InstanceAndEventsRepository.cs
@@ -0,0 +1,41 @@
+using System.Data;
+using Altinn.Platform.Storage.Interface.Models;
+
+namespace Altinn.Platform.Storage.Repository;
+
+/// <summary>
+/// Represents an implementation of <see cref="IInstanceAndEventsRepository"/>.
+/// </summary>
+public class InstanceAndEventsRepository : IInstanceAndEventsRepository 
+{
+    private readonly ILogger<InstanceAndEventsRepository> _logger;
+    private readonly IInstanceRepository _instanceRepository;
+    private readonly IInstanceEventRepository _instanceEventRepository;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="InstanceAndEventsRepository"/> class.
+    /// </summary>
+    /// <param name="logger">The logger to use when writing to logs.</param>
+    /// <param name="instanceRepository">Instance repo</param>
+    public InstanceAndEventsRepository(
+        ILogger<InstanceAndEventsRepository> logger,
+        IInstanceRepository instanceRepository,
+        IInstanceEventRepository instanceEventRepository)
+    {
+        _logger = logger;
+        _instanceRepository = instanceRepository;
+        _instanceEventRepository = instanceEventRepository;
+    }
+
+    /// <inheritdoc/>
+    public async Task<Instance> Update(Instance instance, List<string> updateProperties, List<InstanceEvent> events)
+    {
+        instance = await _instanceRepository.Update(instance);
+        foreach (var instanceEvent in events)
+        {
+            await _instanceEventRepository.InsertInstanceEvent(instanceEvent);
+        }
+
+        return instance;
+    }
+}
diff --git a/src/Services/Storage/Implementation/InstanceEventRepository.cs b/src/Services/Storage/Implementation/InstanceEventRepository.cs
index 6728bec5..5143188d 100644
--- a/src/Services/Storage/Implementation/InstanceEventRepository.cs
+++ b/src/Services/Storage/Implementation/InstanceEventRepository.cs
@@ -83,6 +83,14 @@ public Task<List<InstanceEvent>> ListInstanceEvents(string instanceId, string[]
 
         private string GetInstanceEventPath(string instanceId, Guid instanceEventID)
         {
+            if (string.IsNullOrEmpty(instanceId))
+            {
+                throw new ArgumentException("Instance ID cannot be null or empty");
+            }
+            if (instanceEventID == Guid.Empty)
+            {
+                throw new ArgumentException("Instance event ID cannot be null or empty");
+            }
             return GetInstanceEventFolder() + instanceId.Replace("/", "_") + "_" + instanceEventID.ToString() + ".json";
         }
 
diff --git a/src/Services/Storage/Implementation/InstanceEventService.cs b/src/Services/Storage/Implementation/InstanceEventService.cs
index 438dab17..0f1abfb0 100644
--- a/src/Services/Storage/Implementation/InstanceEventService.cs
+++ b/src/Services/Storage/Implementation/InstanceEventService.cs
@@ -28,7 +28,7 @@ public InstanceEventService(IInstanceEventRepository repository, IHttpContextAcc
         }
 
         /// <inheritdoc/>
-        public async Task DispatchEvent(InstanceEventType eventType, Instance instance)
+        public InstanceEvent BuildInstanceEvent(InstanceEventType eventType, Instance instance)
         {
             var user = _contextAccessor.HttpContext.User;
 
@@ -48,6 +48,14 @@ public async Task DispatchEvent(InstanceEventType eventType, Instance instance)
                 Created = DateTime.UtcNow,
             };
 
+            return instanceEvent;
+        }
+
+        /// <inheritdoc/>
+        public async Task DispatchEvent(InstanceEventType eventType, Instance instance)
+        {
+            var instanceEvent = BuildInstanceEvent(eventType, instance);
+
             await _repository.InsertInstanceEvent(instanceEvent);
         }
 
diff --git a/src/Services/Storage/Interface/IInstanceAndEventsRepository.cs b/src/Services/Storage/Interface/IInstanceAndEventsRepository.cs
new file mode 100644
index 00000000..a1c115fa
--- /dev/null
+++ b/src/Services/Storage/Interface/IInstanceAndEventsRepository.cs
@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Altinn.Platform.Storage.Interface.Models;
+
+namespace Altinn.Platform.Storage.Repository;
+
+/// <summary>
+/// Represents an implementation of <see cref="IInstanceAndEventsRepository"/>.
+/// </summary>
+public interface IInstanceAndEventsRepository 
+{
+    /// <summary>
+    /// update existing instance including instance events
+    /// </summary>
+    /// <param name="instance">the instance to update</param>
+    /// <param name="updateProperties">a list of which properties should be updated</param>
+    /// <param name="events">the events to add</param>
+    /// <returns>The updated instance</returns>
+    Task<Instance> Update(Instance instance, List<string> updateProperties, List<InstanceEvent> events);
+}
diff --git a/src/Services/Storage/Interface/IInstanceEventService.cs b/src/Services/Storage/Interface/IInstanceEventService.cs
index e1878e88..d9534a74 100644
--- a/src/Services/Storage/Interface/IInstanceEventService.cs
+++ b/src/Services/Storage/Interface/IInstanceEventService.cs
@@ -10,6 +10,14 @@ namespace Altinn.Platform.Storage.Services
     /// </summary>
     public interface IInstanceEventService
     {
+        /// <summary>
+        /// Construct an instance event given a type
+        /// </summary>
+        /// <param name="eventType">Event type</param>
+        /// <param name="instance">Instance</param>
+        /// <returns></returns>
+        public InstanceEvent BuildInstanceEvent(InstanceEventType eventType, Instance instance);
+        
         /// <summary>
         /// Dispatch an instance event to the repository
         /// </summary>
diff --git a/src/Startup.cs b/src/Startup.cs
index 03ab99d8..8256fd43 100644
--- a/src/Startup.cs
+++ b/src/Startup.cs
@@ -92,6 +92,7 @@ public void ConfigureServices(IServiceCollection services)
             services.AddSingleton<Altinn.Platform.Authorization.Services.Interface.IParties, PartiesService>();
             services.AddSingleton<IClaims, ClaimsService>();
             services.AddSingleton<IInstanceRepository, InstanceRepository>();
+            services.AddSingleton<IInstanceAndEventsRepository, InstanceAndEventsRepository>();
             services.AddSingleton<IDataRepository, DataRepository>();
             services.AddSingleton<IInstanceEventRepository, InstanceEventRepository>();
             services.AddSingleton<IEventsRepository, EventsRepository>();