diff --git a/src/Core/Services/Implementations/SendService.cs b/src/Core/Services/Implementations/SendService.cs
index 17446863a2..918d816170 100644
--- a/src/Core/Services/Implementations/SendService.cs
+++ b/src/Core/Services/Implementations/SendService.cs
@@ -130,6 +130,11 @@ namespace Bit.Core.Services
 
             var data = JsonConvert.DeserializeObject<SendFileData>(send.Data);
 
+            if (data.Validated)
+            {
+                throw new BadRequestException("File has already been uploaded.");
+            }
+
             await _sendFileStorageService.UploadNewFileAsync(stream, send, data.Id);
 
             if (!await ValidateSendFile(send))
diff --git a/test/Core.Test/Services/OrganizationServiceTests.cs b/test/Core.Test/Services/OrganizationServiceTests.cs
index 385ff6b09f..ecfd225a16 100644
--- a/test/Core.Test/Services/OrganizationServiceTests.cs
+++ b/test/Core.Test/Services/OrganizationServiceTests.cs
@@ -79,6 +79,7 @@ namespace Bit.Core.Test.Services
             List<ImportedOrganizationUser> newUsers)
         {
             org.UseDirectory = true;
+            org.Seats = newUsers.Count + existingUsers.Count + 1;
             var reInvitedUser = existingUsers.First();
             reInvitedUser.ExternalId = null;
             newUsers.Add(new ImportedOrganizationUser