diff --git a/src/Core/AdminConsole/OrganizationFeatures/Organizations/InitPendingOrganizationCommand.cs b/src/Core/AdminConsole/OrganizationFeatures/Organizations/InitPendingOrganizationCommand.cs
index 073fb1e22d..aa6b8240f5 100644
--- a/src/Core/AdminConsole/OrganizationFeatures/Organizations/InitPendingOrganizationCommand.cs
+++ b/src/Core/AdminConsole/OrganizationFeatures/Organizations/InitPendingOrganizationCommand.cs
@@ -268,8 +268,19 @@ public class InitPendingOrganizationCommand : IInitPendingOrganizationCommand
 
     private async Task<Error> ValidatePoliciesAsync(User user, Guid organizationId, Organization org, OrganizationUser orgUser)
     {
-        var autoConfirmReq = await _policyRequirementQuery.GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id);
-        if (autoConfirmReq.CannotCreateNewOrganization() || autoConfirmReq.IsEnabledForOrganizationsOtherThan(organizationId))
+        // Enforce Automatic User Confirmation Policy (when feature flag is enabled)
+        if (_featureService.IsEnabled(FeatureFlagKeys.AutomaticConfirmUsers))
+        {
+            var autoConfirmReq = await _policyRequirementQuery.GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id);
+            if (autoConfirmReq.CannotCreateNewOrganization())
+            {
+                return new SingleOrgPolicyViolationError();
+            }
+        }
+
+        // Enforce Single Organization Policy
+        var anySingleOrgPolicies = await _policyService.AnyPoliciesApplicableToUserAsync(user.Id, PolicyType.SingleOrg);
+        if (anySingleOrgPolicies)
         {
             return new SingleOrgPolicyViolationError();
         }
diff --git a/test/Core.Test/AdminConsole/OrganizationFeatures/Organizations/InitPendingOrganizationCommandTests.cs b/test/Core.Test/AdminConsole/OrganizationFeatures/Organizations/InitPendingOrganizationCommandTests.cs
index 8ab467fe6a..f295cb8431 100644
--- a/test/Core.Test/AdminConsole/OrganizationFeatures/Organizations/InitPendingOrganizationCommandTests.cs
+++ b/test/Core.Test/AdminConsole/OrganizationFeatures/Organizations/InitPendingOrganizationCommandTests.cs
@@ -1,8 +1,10 @@
 using Bit.Core.AdminConsole.Entities;
+using Bit.Core.AdminConsole.Enums;
 using Bit.Core.AdminConsole.Models.Data.Organizations.Policies;
 using Bit.Core.AdminConsole.OrganizationFeatures.OrganizationUsers;
 using Bit.Core.AdminConsole.OrganizationFeatures.Policies;
 using Bit.Core.AdminConsole.OrganizationFeatures.Policies.PolicyRequirements;
+using Bit.Core.AdminConsole.Services;
 using Bit.Core.Auth.Models.Business.Tokenables;
 using Bit.Core.Auth.UserFeatures.TwoFactorAuth.Interfaces;
 using Bit.Core.Billing.Enums;
@@ -198,9 +200,11 @@ public class InitPendingOrganizationCommandTests
         var autoConfirmReq = new AutomaticUserConfirmationPolicyRequirement(new List<PolicyDetails>());
         var twoFactorReq = new RequireTwoFactorPolicyRequirement(new List<PolicyDetails>());
         sutProvider.GetDependency<IPolicyRequirementQuery>()
-            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id).Returns(autoConfirmReq);
+            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id)
+            .Returns(autoConfirmReq);
         sutProvider.GetDependency<IPolicyRequirementQuery>()
-            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id).Returns(twoFactorReq);
+            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id)
+            .Returns(twoFactorReq);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -215,19 +219,46 @@ public class InitPendingOrganizationCommandTests
         Assert.Equal(user.Id, orgUser.UserId);
         Assert.Equal(userKey, orgUser.Key);
         Assert.Null(orgUser.Email);
-        await sutProvider.GetDependency<IOrganizationService>().Received().UpdateAsync(org);
-        await sutProvider.GetDependency<IOrganizationUserRepository>().Received().ReplaceAsync(orgUser);
-        await sutProvider.GetDependency<IEventService>().Received()
+
+        await sutProvider.GetDependency<IOrganizationService>()
+            .Received(1)
+            .UpdateAsync(org);
+        await sutProvider.GetDependency<IOrganizationUserRepository>()
+            .Received(1)
+            .ReplaceAsync(orgUser);
+        await sutProvider.GetDependency<IEventService>()
+            .Received(1)
             .LogOrganizationUserEventAsync(orgUser, EventType.OrganizationUser_Confirmed);
     }
 
+    [Theory, BitAutoData]
+    public async Task InitPendingOrganizationVNextAsync_WithNullOrgUser_ReturnsOrganizationUserNotFoundError(
+        User user, Guid orgId, Guid orgUserId, string publicKey, string privateKey, string userKey,
+        SutProvider<InitPendingOrganizationCommand> sutProvider)
+    {
+        // Arrange
+        sutProvider.GetDependency<IOrganizationUserRepository>()
+            .GetByIdAsync(orgUserId)
+            .Returns((OrganizationUser)null);
+
+        // Act
+        var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
+            user, orgId, orgUserId, publicKey, privateKey, "", "token", userKey);
+
+        // Assert
+        Assert.True(result.IsError);
+        Assert.IsType<OrganizationUserNotFoundError>(result.AsError);
+    }
+
     [Theory, BitAutoData]
     public async Task InitPendingOrganizationVNextAsync_WithInvalidToken_ReturnsInvalidTokenError(
         User user, Guid orgId, Guid orgUserId, string publicKey, string privateKey, string userKey,
         SutProvider<InitPendingOrganizationCommand> sutProvider, OrganizationUser orgUser)
     {
         // Arrange
-        sutProvider.GetDependency<IOrganizationUserRepository>().GetByIdAsync(orgUserId).Returns(orgUser);
+        sutProvider.GetDependency<IOrganizationUserRepository>()
+            .GetByIdAsync(orgUserId)
+            .Returns(orgUser);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -249,7 +280,9 @@ public class InitPendingOrganizationCommandTests
         var token = CreateToken(orgUser, orgUserId, sutProvider);
         org.Enabled = true;
 
-        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns(org);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -272,7 +305,9 @@ public class InitPendingOrganizationCommandTests
         org.Enabled = false;
         org.Status = OrganizationStatusType.Created;
 
-        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns(org);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -296,7 +331,9 @@ public class InitPendingOrganizationCommandTests
         org.Status = OrganizationStatusType.Pending;
         org.PublicKey = "existing-key";
 
-        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns(org);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -307,6 +344,29 @@ public class InitPendingOrganizationCommandTests
         Assert.IsType<OrganizationHasKeysError>(result.AsError);
     }
 
+    [Theory, BitAutoData]
+    public async Task InitPendingOrganizationVNextAsync_WithNullOrganization_ReturnsOrganizationNotFoundError(
+        User user, Guid orgId, Guid orgUserId, string publicKey, string privateKey, string userKey,
+        SutProvider<InitPendingOrganizationCommand> sutProvider, OrganizationUser orgUser)
+    {
+        // Arrange
+        orgUser.Email = user.Email;
+        orgUser.OrganizationId = orgId;
+        var token = CreateToken(orgUser, orgUserId, sutProvider);
+
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns((Organization)null);
+
+        // Act
+        var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
+            user, orgId, orgUserId, publicKey, privateKey, "", token, userKey);
+
+        // Assert
+        Assert.True(result.IsError);
+        Assert.IsType<OrganizationNotFoundError>(result.AsError);
+    }
+
     [Theory, BitAutoData]
     public async Task InitPendingOrganizationVNextAsync_WithEmailMismatch_ReturnsEmailMismatchError(
         User user, Guid orgId, Guid orgUserId, string publicKey, string privateKey, string userKey,
@@ -317,7 +377,9 @@ public class InitPendingOrganizationCommandTests
         orgUser.OrganizationId = orgId;
         var token = CreateToken(orgUser, orgUserId, sutProvider);
 
-        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns(org);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -344,15 +406,21 @@ public class InitPendingOrganizationCommandTests
         org.PrivateKey = null;
         org.PublicKey = null;
 
-        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
-        sutProvider.GetDependency<ITwoFactorIsEnabledQuery>().TwoFactorIsEnabledAsync(user).Returns(true);
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns(org);
+        sutProvider.GetDependency<ITwoFactorIsEnabledQuery>()
+            .TwoFactorIsEnabledAsync(user)
+            .Returns(true);
 
         var autoConfirmReq = new AutomaticUserConfirmationPolicyRequirement(new List<PolicyDetails>());
         var twoFactorReq = new RequireTwoFactorPolicyRequirement(new List<PolicyDetails>());
         sutProvider.GetDependency<IPolicyRequirementQuery>()
-            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id).Returns(autoConfirmReq);
+            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id)
+            .Returns(autoConfirmReq);
         sutProvider.GetDependency<IPolicyRequirementQuery>()
-            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id).Returns(twoFactorReq);
+            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id)
+            .Returns(twoFactorReq);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -380,17 +448,23 @@ public class InitPendingOrganizationCommandTests
         org.PrivateKey = null;
         org.PublicKey = null;
 
-        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
-        sutProvider.GetDependency<ITwoFactorIsEnabledQuery>().TwoFactorIsEnabledAsync(user).Returns(false);
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns(org);
+        sutProvider.GetDependency<ITwoFactorIsEnabledQuery>()
+            .TwoFactorIsEnabledAsync(user)
+            .Returns(false);
 
         var autoConfirmReq = new AutomaticUserConfirmationPolicyRequirement(new List<PolicyDetails>());
         var twoFactorReq = new RequireTwoFactorPolicyRequirement(
             new List<PolicyDetails> { new PolicyDetails { OrganizationId = orgId } });
 
         sutProvider.GetDependency<IPolicyRequirementQuery>()
-            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id).Returns(autoConfirmReq);
+            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id)
+            .Returns(autoConfirmReq);
         sutProvider.GetDependency<IPolicyRequirementQuery>()
-            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id).Returns(twoFactorReq);
+            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id)
+            .Returns(twoFactorReq);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -417,16 +491,21 @@ public class InitPendingOrganizationCommandTests
         org.PublicKey = null;
         org.PlanType = PlanType.Free;
 
-        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns(org);
         sutProvider.GetDependency<IOrganizationUserRepository>()
-            .GetCountByFreeOrganizationAdminUserAsync(user.Id).Returns(1);
+            .GetCountByFreeOrganizationAdminUserAsync(user.Id)
+            .Returns(1);
 
         var autoConfirmReq = new AutomaticUserConfirmationPolicyRequirement(new List<PolicyDetails>());
         var twoFactorReq = new RequireTwoFactorPolicyRequirement(new List<PolicyDetails>());
         sutProvider.GetDependency<IPolicyRequirementQuery>()
-            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id).Returns(autoConfirmReq);
+            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id)
+            .Returns(autoConfirmReq);
         sutProvider.GetDependency<IPolicyRequirementQuery>()
-            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id).Returns(twoFactorReq);
+            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id)
+            .Returns(twoFactorReq);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
@@ -437,6 +516,92 @@ public class InitPendingOrganizationCommandTests
         Assert.IsType<FreeOrgAdminLimitError>(result.AsError);
     }
 
+    [Theory, BitAutoData]
+    public async Task InitPendingOrganizationVNextAsync_WithAutomaticUserConfirmationPolicy_ReturnsSingleOrgPolicyViolationError(
+        User user, Guid orgId, Guid orgUserId, Guid otherOrgId, string publicKey, string privateKey, string userKey,
+        SutProvider<InitPendingOrganizationCommand> sutProvider, Organization org, OrganizationUser orgUser)
+    {
+        // Arrange
+        orgUser.Email = user.Email;
+        orgUser.OrganizationId = orgId;
+        var token = CreateToken(orgUser, orgUserId, sutProvider);
+        org.Enabled = false;
+        org.Status = OrganizationStatusType.Pending;
+        org.PrivateKey = null;
+        org.PublicKey = null;
+
+        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
+
+        // Enable AutomaticConfirmUsers feature flag
+        sutProvider.GetDependency<IFeatureService>()
+            .IsEnabled(FeatureFlagKeys.AutomaticConfirmUsers)
+            .Returns(true);
+
+        // User is subject to AutomaticUserConfirmation policy from another organization
+        var autoConfirmReq = new AutomaticUserConfirmationPolicyRequirement(
+            new List<PolicyDetails> { new PolicyDetails { OrganizationId = otherOrgId } });
+        var twoFactorReq = new RequireTwoFactorPolicyRequirement(new List<PolicyDetails>());
+
+        sutProvider.GetDependency<IPolicyRequirementQuery>()
+            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id)
+            .Returns(autoConfirmReq);
+        sutProvider.GetDependency<IPolicyRequirementQuery>()
+            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id)
+            .Returns(twoFactorReq);
+
+        // No legacy SingleOrg policy
+        sutProvider.GetDependency<IPolicyService>()
+            .AnyPoliciesApplicableToUserAsync(user.Id, PolicyType.SingleOrg).Returns(false);
+
+        // Act
+        var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
+            user, orgId, orgUserId, publicKey, privateKey, "", token, userKey);
+
+        // Assert
+        Assert.True(result.IsError);
+        Assert.IsType<SingleOrgPolicyViolationError>(result.AsError);
+    }
+
+    [Theory, BitAutoData]
+    public async Task InitPendingOrganizationVNextAsync_WithSingleOrgPolicy_ReturnsSingleOrgPolicyViolationError(
+        User user, Guid orgId, Guid orgUserId, string publicKey, string privateKey, string userKey,
+        SutProvider<InitPendingOrganizationCommand> sutProvider, Organization org, OrganizationUser orgUser)
+    {
+        // Arrange
+        orgUser.Email = user.Email;
+        orgUser.OrganizationId = orgId;
+        var token = CreateToken(orgUser, orgUserId, sutProvider);
+        org.Enabled = false;
+        org.Status = OrganizationStatusType.Pending;
+        org.PrivateKey = null;
+        org.PublicKey = null;
+
+        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
+
+        var autoConfirmReq = new AutomaticUserConfirmationPolicyRequirement(new List<PolicyDetails>());
+        var twoFactorReq = new RequireTwoFactorPolicyRequirement(new List<PolicyDetails>());
+
+        sutProvider.GetDependency<IPolicyRequirementQuery>()
+            .GetAsync<AutomaticUserConfirmationPolicyRequirement>(user.Id)
+            .Returns(autoConfirmReq);
+        sutProvider.GetDependency<IPolicyRequirementQuery>()
+            .GetAsync<RequireTwoFactorPolicyRequirement>(user.Id)
+            .Returns(twoFactorReq);
+
+        // User is subject to SingleOrg policy from another organization
+        sutProvider.GetDependency<IPolicyService>()
+            .AnyPoliciesApplicableToUserAsync(user.Id, PolicyType.SingleOrg)
+            .Returns(true);
+
+        // Act
+        var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(
+            user, orgId, orgUserId, publicKey, privateKey, "", token, userKey);
+
+        // Assert
+        Assert.True(result.IsError);
+        Assert.IsType<SingleOrgPolicyViolationError>(result.AsError);
+    }
+
     [Theory, BitAutoData]
     public async Task InitPendingOrganizationVNextAsync_WithMismatchedOrganizationId_ReturnsOrganizationMismatchError(
         User user, Guid orgId, Guid differentOrgId, Guid orgUserId, string publicKey, string privateKey, string userKey,
@@ -453,7 +618,9 @@ public class InitPendingOrganizationCommandTests
         org.PrivateKey = null;
         org.PublicKey = null;
 
-        sutProvider.GetDependency<IOrganizationRepository>().GetByIdAsync(orgId).Returns(org);
+        sutProvider.GetDependency<IOrganizationRepository>()
+            .GetByIdAsync(orgId)
+            .Returns(org);
 
         // Act
         var result = await sutProvider.Sut.InitPendingOrganizationVNextAsync(