diff --git a/EnvelopeGenerator.Application/Model/EnvelopeReceiverQueryBase.cs b/EnvelopeGenerator.Application/Model/EnvelopeReceiverQueryBase.cs
index 80a28b04..51426027 100644
--- a/EnvelopeGenerator.Application/Model/EnvelopeReceiverQueryBase.cs
+++ b/EnvelopeGenerator.Application/Model/EnvelopeReceiverQueryBase.cs
@@ -6,14 +6,14 @@ namespace EnvelopeGenerator.Application.Model;
 /// <summary>
 /// 
 /// </summary>
-public record EnvelopeReceiverQueryBase : EnvelopeReceiverQueryBase<EnvelopeQueryBase, ReceiverQueryBase>;
+public record EnvelopeReceiverQueryBase : EnvelopeReceiverQueryBase<EnvelopeQueryBase, ReceiverQueryBase>, IHasEnvelopeQuery, IHasReceiverQuery;
 
 /// <summary>
 /// 
 /// </summary>
 /// <typeparam name="TEnvelopeQuery"></typeparam>
 /// <typeparam name="TReceiverQuery"></typeparam>
-public record EnvelopeReceiverQueryBase<TEnvelopeQuery, TReceiverQuery>
+public record EnvelopeReceiverQueryBase<TEnvelopeQuery, TReceiverQuery> : IHasEnvelopeQuery<TEnvelopeQuery>, IHasReceiverQuery<TReceiverQuery>
     where TEnvelopeQuery : EnvelopeQueryBase, new()
     where TReceiverQuery : ReceiverQueryBase, new()
 {
@@ -25,7 +25,7 @@ public record EnvelopeReceiverQueryBase<TEnvelopeQuery, TReceiverQuery>
     public virtual string? Key
     {
         get => _key;
-        init
+        set
         {
             if (value is null)
             {
@@ -52,11 +52,11 @@ public record EnvelopeReceiverQueryBase<TEnvelopeQuery, TReceiverQuery>
     /// <summary>
     /// Repräsentiert eine Abfrage für Umschläge.
     /// </summary>
-    public virtual TEnvelopeQuery Envelope { get; init; } = new();
+    public virtual TEnvelopeQuery Envelope { get; set; } = new();
 
     /// <summary>
     /// Stellt eine Abfrage dar, um die Details eines Empfängers zu lesen.
     /// um spezifische Informationen über einen Empfänger abzurufen.
     /// </summary>
-    public virtual TReceiverQuery Receiver { get; init; } = new();
+    public virtual TReceiverQuery Receiver { get; set; } = new();
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Application/Model/IHasEnvelopeQuery.cs b/EnvelopeGenerator.Application/Model/IHasEnvelopeQuery.cs
new file mode 100644
index 00000000..2a65a081
--- /dev/null
+++ b/EnvelopeGenerator.Application/Model/IHasEnvelopeQuery.cs
@@ -0,0 +1,21 @@
+namespace EnvelopeGenerator.Application.Model;
+
+/// <summary>
+/// 
+/// </summary>
+public interface IHasEnvelopeQuery<TEnvelopeQuery>
+    where TEnvelopeQuery : EnvelopeQueryBase
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public TEnvelopeQuery Envelope { get; set; }
+}
+
+/// <summary>
+/// 
+/// </summary>
+public interface IHasEnvelopeQuery
+    : IHasEnvelopeQuery<EnvelopeQueryBase>
+{
+}
\ No newline at end of file
diff --git a/EnvelopeGenerator.Application/Model/IHasReceiverQuery.cs b/EnvelopeGenerator.Application/Model/IHasReceiverQuery.cs
new file mode 100644
index 00000000..dd887969
--- /dev/null
+++ b/EnvelopeGenerator.Application/Model/IHasReceiverQuery.cs
@@ -0,0 +1,21 @@
+namespace EnvelopeGenerator.Application.Model;
+
+/// <summary>
+/// 
+/// </summary>
+public interface IHasReceiverQuery<TReceiverQuery>
+    where TReceiverQuery : ReceiverQueryBase
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public TReceiverQuery Receiver { get; set; }
+}
+
+/// <summary>
+/// 
+/// </summary>
+public interface IHasReceiverQuery
+    : IHasReceiverQuery<ReceiverQueryBase>
+{
+}
\ No newline at end of file