diff --git a/src/Api/Controllers/OrganizationUsersController.cs b/src/Api/Controllers/OrganizationUsersController.cs
index 8f10f9d2d..2c5c08f11 100644
--- a/src/Api/Controllers/OrganizationUsersController.cs
+++ b/src/Api/Controllers/OrganizationUsersController.cs
@@ -58,7 +58,7 @@ namespace Bit.Api.Controllers
         public async Task Invite(string orgId, [FromBody]OrganizationUserInviteRequestModel model)
         {
             var userId = _userService.GetProperUserId(User);
-            var result = await _organizationService.InviteUserAsync(new Guid(orgId), userId.Value, model.Email, model.Type,
+            var result = await _organizationService.InviteUserAsync(new Guid(orgId), userId.Value, model.Email, model.Type.Value,
                 model.Subvaults?.Select(s => s.ToSubvaultUser()));
         }
 
diff --git a/src/Core/Models/Api/Request/Organizations/OrganizationUserRequestModels.cs b/src/Core/Models/Api/Request/Organizations/OrganizationUserRequestModels.cs
index 7d9c41f8e..d9bfe59dc 100644
--- a/src/Core/Models/Api/Request/Organizations/OrganizationUserRequestModels.cs
+++ b/src/Core/Models/Api/Request/Organizations/OrganizationUserRequestModels.cs
@@ -1,40 +1,48 @@
 using Bit.Core.Models.Table;
 using System;
 using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
 
 namespace Bit.Core.Models.Api
 {
     public class OrganizationUserInviteRequestModel
     {
+        [Required]
+        [EmailAddress]
         public string Email { get; set; }
-        public Enums.OrganizationUserType Type { get; set; }
+        [Required]
+        public Enums.OrganizationUserType? Type { get; set; }
         public IEnumerable<OrganizationUserSubvaultRequestModel> Subvaults { get; set; }
     }
 
     public class OrganizationUserAcceptRequestModel
     {
+        [Required]
         public string Token { get; set; }
     }
 
     public class OrganizationUserConfirmRequestModel
     {
+        [Required]
         public string Key { get; set; }
     }
 
     public class OrganizationUserUpdateRequestModel
     {
-        public Enums.OrganizationUserType Type { get; set; }
+        [Required]
+        public Enums.OrganizationUserType? Type { get; set; }
         public IEnumerable<OrganizationUserSubvaultRequestModel> Subvaults { get; set; }
 
         public OrganizationUser ToOrganizationUser(OrganizationUser existingUser)
         {
-            existingUser.Type = Type;
+            existingUser.Type = Type.Value;
             return existingUser;
         }
     }
 
     public class OrganizationUserSubvaultRequestModel
     {
+        [Required]
         public string SubvaultId { get; set; }
         public bool Admin { get; set; }
         public bool ReadOnly { get; set; }
@@ -44,14 +52,10 @@ namespace Bit.Core.Models.Api
             var subvault = new SubvaultUser
             {
                 Admin = Admin,
-                ReadOnly = ReadOnly
+                ReadOnly = ReadOnly,
+                SubvaultId = new Guid(SubvaultId)
             };
 
-            if(!string.IsNullOrWhiteSpace(SubvaultId))
-            {
-                subvault.SubvaultId = new Guid(SubvaultId);
-            }
-
             return subvault;
         }
     }