diff --git a/test/Core.Test/Services/OrganizationServiceTests.cs b/test/Core.Test/Services/OrganizationServiceTests.cs
new file mode 100644
index 000000000..ebf10f75c
--- /dev/null
+++ b/test/Core.Test/Services/OrganizationServiceTests.cs
@@ -0,0 +1,130 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Bit.Core.Models.Data;
+using Bit.Core.Models.Table;
+using Bit.Core.Repositories;
+using Bit.Core.Services;
+using Microsoft.AspNetCore.DataProtection;
+using NSubstitute;
+using Xunit;
+
+namespace Bit.Core.Test.Services
+{
+    public class OrganizationServiceTests
+    {
+        [Fact]
+        public async Task OrgImportCreateNewUsers()
+        {
+            var orgRepo = Substitute.For<IOrganizationRepository>();
+            var orgUserRepo = Substitute.For<IOrganizationUserRepository>();
+            var collectionRepo = Substitute.For<ICollectionRepository>();
+            var userRepo = Substitute.For<IUserRepository>();
+            var groupRepo = Substitute.For<IGroupRepository>();
+            var dataProtector = Substitute.For<IDataProtector>();
+            var mailService = Substitute.For<IMailService>();
+            var pushNotService = Substitute.For<IPushNotificationService>();
+            var pushRegService = Substitute.For<IPushRegistrationService>();
+            var deviceRepo = Substitute.For<IDeviceRepository>();
+            var licenseService = Substitute.For<ILicensingService>();
+            var eventService = Substitute.For<IEventService>();
+            var installationRepo = Substitute.For<IInstallationRepository>();
+            var appCacheService = Substitute.For<IApplicationCacheService>();
+            var paymentService = Substitute.For<IPaymentService>();
+            var globalSettings = Substitute.For<GlobalSettings>();
+
+            var orgService = new OrganizationService(orgRepo, orgUserRepo, collectionRepo, userRepo,
+                groupRepo, dataProtector, mailService, pushNotService, pushRegService, deviceRepo,
+                licenseService, eventService, installationRepo, appCacheService, paymentService, globalSettings);
+
+            var id = Guid.NewGuid();
+            var userId = Guid.NewGuid();
+            var org = new Organization
+            {
+                Id = id,
+                Name = "Test Org",
+                UseDirectory = true,
+                UseGroups = true,
+                Seats = 3
+            };
+            orgRepo.GetByIdAsync(id).Returns(org);
+
+            var existingUsers = new List<OrganizationUserUserDetails>();
+            existingUsers.Add(new OrganizationUserUserDetails
+            {
+                Id = Guid.NewGuid(),
+                ExternalId = "a",
+                Email = "a@test.com"
+            });
+            orgUserRepo.GetManyDetailsByOrganizationAsync(id).Returns(existingUsers);
+            orgUserRepo.GetCountByOrganizationIdAsync(id).Returns(1);
+
+            var newUsers = new List<Models.Business.ImportedOrganizationUser>();
+            newUsers.Add(new Models.Business.ImportedOrganizationUser { Email = "a@test.com", ExternalId = "a" });
+            newUsers.Add(new Models.Business.ImportedOrganizationUser { Email = "b@test.com", ExternalId = "b" });
+            newUsers.Add(new Models.Business.ImportedOrganizationUser { Email = "c@test.com", ExternalId = "c" });
+            await orgService.ImportAsync(id, userId, null, newUsers, null);
+
+            await orgUserRepo.DidNotReceive().UpsertAsync(Arg.Any<OrganizationUser>());
+            await orgUserRepo.Received(2).CreateAsync(Arg.Any<OrganizationUser>());
+        }
+
+        [Fact]
+        public async Task OrgImportCreateNewUsersAndMarryExistingUser()
+        {
+            var orgRepo = Substitute.For<IOrganizationRepository>();
+            var orgUserRepo = Substitute.For<IOrganizationUserRepository>();
+            var collectionRepo = Substitute.For<ICollectionRepository>();
+            var userRepo = Substitute.For<IUserRepository>();
+            var groupRepo = Substitute.For<IGroupRepository>();
+            var dataProtector = Substitute.For<IDataProtector>();
+            var mailService = Substitute.For<IMailService>();
+            var pushNotService = Substitute.For<IPushNotificationService>();
+            var pushRegService = Substitute.For<IPushRegistrationService>();
+            var deviceRepo = Substitute.For<IDeviceRepository>();
+            var licenseService = Substitute.For<ILicensingService>();
+            var eventService = Substitute.For<IEventService>();
+            var installationRepo = Substitute.For<IInstallationRepository>();
+            var appCacheService = Substitute.For<IApplicationCacheService>();
+            var paymentService = Substitute.For<IPaymentService>();
+            var globalSettings = Substitute.For<GlobalSettings>();
+
+            var orgService = new OrganizationService(orgRepo, orgUserRepo, collectionRepo, userRepo,
+                groupRepo, dataProtector, mailService, pushNotService, pushRegService, deviceRepo,
+                licenseService, eventService, installationRepo, appCacheService, paymentService, globalSettings);
+
+            var id = Guid.NewGuid();
+            var userId = Guid.NewGuid();
+            var org = new Organization
+            {
+                Id = id,
+                Name = "Test Org",
+                UseDirectory = true,
+                UseGroups = true,
+                Seats = 3
+            };
+            orgRepo.GetByIdAsync(id).Returns(org);
+
+            var existingUserAId = Guid.NewGuid();
+            var existingUsers = new List<OrganizationUserUserDetails>();
+            existingUsers.Add(new OrganizationUserUserDetails
+            {
+                Id = existingUserAId,
+                // No external id here
+                Email = "a@test.com"
+            });
+            orgUserRepo.GetManyDetailsByOrganizationAsync(id).Returns(existingUsers);
+            orgUserRepo.GetCountByOrganizationIdAsync(id).Returns(1);
+            orgUserRepo.GetByIdAsync(existingUserAId).Returns(new OrganizationUser { Id = existingUserAId });
+
+            var newUsers = new List<Models.Business.ImportedOrganizationUser>();
+            newUsers.Add(new Models.Business.ImportedOrganizationUser { Email = "a@test.com", ExternalId = "a" });
+            newUsers.Add(new Models.Business.ImportedOrganizationUser { Email = "b@test.com", ExternalId = "b" });
+            newUsers.Add(new Models.Business.ImportedOrganizationUser { Email = "c@test.com", ExternalId = "c" });
+            await orgService.ImportAsync(id, userId, null, newUsers, null);
+
+            await orgUserRepo.Received(1).UpsertAsync(Arg.Any<OrganizationUser>());
+            await orgUserRepo.Received(2).CreateAsync(Arg.Any<OrganizationUser>());
+        }
+    }
+}