diff --git a/DataLayer/DataLayer.csproj b/DataLayer/DataLayer.csproj
index b24604f..a7fd617 100644
--- a/DataLayer/DataLayer.csproj
+++ b/DataLayer/DataLayer.csproj
@@ -8,11 +8,6 @@
 
   <ItemGroup>
     <PackageReference Include="dbup" Version="5.0.41" />
-    <PackageReference Include="idunno.Password.Generator" Version="1.0.1" />
-    <PackageReference
-      Include="Konscious.Security.Cryptography.Argon2"
-      Version="1.3.1"
-    />
     <PackageReference Include="Microsoft.Data.SqlClient" Version="6.1.2" />
   </ItemGroup>
   <ItemGroup>
diff --git a/DataLayer/scripts/03-crud/02-UserCredential/USP_AddUserCredential.sql b/DataLayer/scripts/03-crud/02-UserCredential/USP_AddUserCredential.sql
index 99077b8..bd9395e 100644
--- a/DataLayer/scripts/03-crud/02-UserCredential/USP_AddUserCredential.sql
+++ b/DataLayer/scripts/03-crud/02-UserCredential/USP_AddUserCredential.sql
@@ -9,6 +9,21 @@ BEGIN
 
     BEGIN TRANSACTION;
 
+    IF NOT EXISTS (
+        SELECT 1 
+        FROM dbo.UserAccount 
+        WHERE UserAccountID = @UserAccountId
+    )
+        THROW 50001, 'UserAccountID does not exist.', 1;
+    
+    IF EXISTS (
+        SELECT 1 
+        FROM dbo.UserCredential
+        WHERE UserAccountID = @UserAccountId
+    )
+        THROW 50002, 'UserCredential for this UserAccountID already exists.', 1;
+    
+
     INSERT INTO dbo.UserCredential
         (UserAccountId, Hash)
     VALUES