diff --git a/src/Core/Auth/Models/Api/Request/Accounts/RegisterFinishRequestModel.cs b/src/Core/Auth/Models/Api/Request/Accounts/RegisterFinishRequestModel.cs
index d9b3e10da..9036651fd 100644
--- a/src/Core/Auth/Models/Api/Request/Accounts/RegisterFinishRequestModel.cs
+++ b/src/Core/Auth/Models/Api/Request/Accounts/RegisterFinishRequestModel.cs
@@ -33,6 +33,9 @@ public class RegisterFinishRequestModel : IValidatableObject
 
     public string? OrgSponsoredFreeFamilyPlanToken { get; set; }
 
+    public string? AcceptEmergencyAccessInviteToken { get; set; }
+    public Guid? AcceptEmergencyAccessId { get; set; }
+
     public User ToUser()
     {
         var user = new User
diff --git a/src/Core/Auth/UserFeatures/Registration/IRegisterUserCommand.cs b/src/Core/Auth/UserFeatures/Registration/IRegisterUserCommand.cs
index bd742de8b..d507cda4e 100644
--- a/src/Core/Auth/UserFeatures/Registration/IRegisterUserCommand.cs
+++ b/src/Core/Auth/UserFeatures/Registration/IRegisterUserCommand.cs
@@ -34,9 +34,31 @@ public interface IRegisterUserCommand
     /// <param name="user">The <see cref="User"/> to create</param>
     /// <param name="masterPasswordHash">The hashed master password the user entered</param>
     /// <param name="emailVerificationToken">The email verification token sent to the user via email</param>
-    /// <returns></returns>
+    /// <returns><see cref="IdentityResult"/></returns>
     public Task<IdentityResult> RegisterUserViaEmailVerificationToken(User user, string masterPasswordHash, string emailVerificationToken);
 
+    /// <summary>
+    /// Creates a new user with a given master password hash, sends a welcome email, and raises the signup reference event.
+    /// If a valid org sponsored free family plan invite token is provided, the user will be created with their email verified.
+    /// If the token is invalid or expired, an error will be thrown.
+    /// </summary>
+    /// <param name="user">The <see cref="User"/> to create</param>
+    /// <param name="masterPasswordHash">The hashed master password the user entered</param>
+    /// <param name="orgSponsoredFreeFamilyPlanInviteToken">The org sponsored free family plan invite token sent to the user via email</param>
+    /// <returns><see cref="IdentityResult"/></returns>
     public Task<IdentityResult> RegisterUserViaOrganizationSponsoredFreeFamilyPlanInviteToken(User user, string masterPasswordHash, string orgSponsoredFreeFamilyPlanInviteToken);
 
+    /// <summary>
+    /// Creates a new user with a given master password hash, sends a welcome email, and raises the signup reference event.
+    /// If a valid token is provided, the user will be created with their email verified.
+    /// If the token is invalid or expired, an error will be thrown.
+    /// </summary>
+    /// <param name="user">The <see cref="User"/> to create</param>
+    /// <param name="masterPasswordHash">The hashed master password the user entered</param>
+    /// <param name="acceptEmergencyAccessInviteToken">The emergency access invite token sent to the user via email</param>
+    /// <param name="acceptEmergencyAccessId">The emergency access id (used to validate the token)</param>
+    /// <returns><see cref="IdentityResult"/></returns>
+    public Task<IdentityResult> RegisterUserViaAcceptEmergencyAccessInviteToken(User user, string masterPasswordHash,
+        string acceptEmergencyAccessInviteToken, Guid acceptEmergencyAccessId);
+
 }
diff --git a/src/Core/Auth/UserFeatures/Registration/Implementations/RegisterUserCommand.cs b/src/Core/Auth/UserFeatures/Registration/Implementations/RegisterUserCommand.cs
index 937a44e82..3bbdaaf0a 100644
--- a/src/Core/Auth/UserFeatures/Registration/Implementations/RegisterUserCommand.cs
+++ b/src/Core/Auth/UserFeatures/Registration/Implementations/RegisterUserCommand.cs
@@ -40,6 +40,8 @@ public class RegisterUserCommand : IRegisterUserCommand
 
     private readonly IValidateRedemptionTokenCommand _validateRedemptionTokenCommand;
 
+    private readonly IDataProtectorTokenFactory<EmergencyAccessInviteTokenable> _emergencyAccessInviteTokenDataFactory;
+
     private readonly string _disabledUserRegistrationExceptionMsg = "Open registration has been disabled by the system administrator.";
 
     public RegisterUserCommand(
@@ -53,7 +55,8 @@ public class RegisterUserCommand : IRegisterUserCommand
         ICurrentContext currentContext,
         IUserService userService,
         IMailService mailService,
-        IValidateRedemptionTokenCommand validateRedemptionTokenCommand
+        IValidateRedemptionTokenCommand validateRedemptionTokenCommand,
+        IDataProtectorTokenFactory<EmergencyAccessInviteTokenable> emergencyAccessInviteTokenDataFactory
         )
     {
         _globalSettings = globalSettings;
@@ -71,6 +74,7 @@ public class RegisterUserCommand : IRegisterUserCommand
         _mailService = mailService;
 
         _validateRedemptionTokenCommand = validateRedemptionTokenCommand;
+        _emergencyAccessInviteTokenDataFactory = emergencyAccessInviteTokenDataFactory;
     }
 
 
@@ -278,6 +282,27 @@ public class RegisterUserCommand : IRegisterUserCommand
         return result;
     }
 
+
+    // TODO: in future, consider how we can consolidate base registration logic to reduce code duplication
+    public async Task<IdentityResult> RegisterUserViaAcceptEmergencyAccessInviteToken(User user, string masterPasswordHash,
+        string acceptEmergencyAccessInviteToken, Guid acceptEmergencyAccessId)
+    {
+        ValidateOpenRegistrationAllowed();
+        ValidateAcceptEmergencyAccessInviteToken(acceptEmergencyAccessInviteToken, acceptEmergencyAccessId, user.Email);
+
+        user.EmailVerified = true;
+        user.ApiKey = CoreHelpers.SecureRandomString(30); // API key can't be null.
+
+        var result = await _userService.CreateUserAsync(user, masterPasswordHash);
+        if (result == IdentityResult.Success)
+        {
+            await _mailService.SendWelcomeEmailAsync(user);
+            await _referenceEventService.RaiseEventAsync(new ReferenceEvent(ReferenceEventType.Signup, user, _currentContext));
+        }
+
+        return result;
+    }
+
     private void ValidateOpenRegistrationAllowed()
     {
         // We validate open registration on send of initial email and here b/c a user could technically start the
@@ -297,7 +322,15 @@ public class RegisterUserCommand : IRegisterUserCommand
         {
             throw new BadRequestException("Invalid org sponsored free family plan token.");
         }
+    }
 
+    private void ValidateAcceptEmergencyAccessInviteToken(string acceptEmergencyAccessInviteToken, Guid acceptEmergencyAccessId, string userEmail)
+    {
+        _emergencyAccessInviteTokenDataFactory.TryUnprotect(acceptEmergencyAccessInviteToken, out var tokenable);
+        if (tokenable == null || !tokenable.Valid || !tokenable.IsValid(acceptEmergencyAccessId, userEmail))
+        {
+            throw new BadRequestException("Invalid accept emergency access invite token.");
+        }
     }
 
 
diff --git a/src/Identity/Controllers/AccountsController.cs b/src/Identity/Controllers/AccountsController.cs
index 74a58ee2f..38316566c 100644
--- a/src/Identity/Controllers/AccountsController.cs
+++ b/src/Identity/Controllers/AccountsController.cs
@@ -144,7 +144,7 @@ public class AccountsController : Controller
     {
         var user = model.ToUser();
 
-        // Users will either have an org invite token or an email verification token - not both.
+        // Users will either have an emailed token or an email verification token - not both.
 
         IdentityResult identityResult = null;
         var delaysEnabled = !_featureService.IsEnabled(FeatureFlagKeys.EmailVerificationDisableTimingDelays);
@@ -164,9 +164,25 @@ public class AccountsController : Controller
             return await ProcessRegistrationResult(identityResult, user, delaysEnabled);
         }
 
-        identityResult = await _registerUserCommand.RegisterUserViaEmailVerificationToken(user, model.MasterPasswordHash, model.EmailVerificationToken);
+        if (!string.IsNullOrEmpty(model.AcceptEmergencyAccessInviteToken) && model.AcceptEmergencyAccessId.HasValue)
+        {
+            identityResult = await _registerUserCommand.RegisterUserViaAcceptEmergencyAccessInviteToken(user, model.MasterPasswordHash,
+                model.AcceptEmergencyAccessInviteToken, model.AcceptEmergencyAccessId.Value);
+
+            return await ProcessRegistrationResult(identityResult, user, delaysEnabled);
+        }
+
+        if (string.IsNullOrEmpty(model.EmailVerificationToken))
+        {
+            throw new BadRequestException("Invalid registration finish request");
+        }
+
+        identityResult =
+            await _registerUserCommand.RegisterUserViaEmailVerificationToken(user, model.MasterPasswordHash,
+                model.EmailVerificationToken);
 
         return await ProcessRegistrationResult(identityResult, user, delaysEnabled);
+
     }
 
     private async Task<RegisterResponseModel> ProcessRegistrationResult(IdentityResult result, User user, bool delaysEnabled)
diff --git a/test/Core.Test/Auth/UserFeatures/Registration/RegisterUserCommandTests.cs b/test/Core.Test/Auth/UserFeatures/Registration/RegisterUserCommandTests.cs
index 60db00ab9..e96e3553d 100644
--- a/test/Core.Test/Auth/UserFeatures/Registration/RegisterUserCommandTests.cs
+++ b/test/Core.Test/Auth/UserFeatures/Registration/RegisterUserCommandTests.cs
@@ -1,6 +1,7 @@
 using Bit.Core.AdminConsole.Entities;
 using Bit.Core.AdminConsole.Enums;
 using Bit.Core.AdminConsole.Repositories;
+using Bit.Core.Auth.Entities;
 using Bit.Core.Auth.Enums;
 using Bit.Core.Auth.Models;
 using Bit.Core.Auth.Models.Business.Tokenables;
@@ -449,7 +450,90 @@ public class RegisterUserCommandTests
         var result = await Assert.ThrowsAsync<BadRequestException>(() =>
             sutProvider.Sut.RegisterUserViaOrganizationSponsoredFreeFamilyPlanInviteToken(user, masterPasswordHash, orgSponsoredFreeFamilyPlanInviteToken));
         Assert.Equal("Open registration has been disabled by the system administrator.", result.Message);
+    }
 
+    // RegisterUserViaAcceptEmergencyAccessInviteToken
+
+    [Theory]
+    [BitAutoData]
+    public async Task RegisterUserViaAcceptEmergencyAccessInviteToken_Succeeds(
+        SutProvider<RegisterUserCommand> sutProvider, User user, string masterPasswordHash,
+        EmergencyAccess emergencyAccess, string acceptEmergencyAccessInviteToken, Guid acceptEmergencyAccessId)
+    {
+        // Arrange
+        emergencyAccess.Email = user.Email;
+        emergencyAccess.Id = acceptEmergencyAccessId;
+
+        sutProvider.GetDependency<IDataProtectorTokenFactory<EmergencyAccessInviteTokenable>>()
+            .TryUnprotect(acceptEmergencyAccessInviteToken, out Arg.Any<EmergencyAccessInviteTokenable>())
+            .Returns(callInfo =>
+            {
+                callInfo[1] = new EmergencyAccessInviteTokenable(emergencyAccess, 10);
+                return true;
+            });
+
+        sutProvider.GetDependency<IUserService>()
+            .CreateUserAsync(user, masterPasswordHash)
+            .Returns(IdentityResult.Success);
+
+        // Act
+        var result = await sutProvider.Sut.RegisterUserViaAcceptEmergencyAccessInviteToken(user, masterPasswordHash, acceptEmergencyAccessInviteToken, acceptEmergencyAccessId);
+
+        // Assert
+        Assert.True(result.Succeeded);
+
+        await sutProvider.GetDependency<IUserService>()
+            .Received(1)
+            .CreateUserAsync(Arg.Is<User>(u => u.Name == user.Name && u.EmailVerified == true && u.ApiKey != null), masterPasswordHash);
+
+        await sutProvider.GetDependency<IMailService>()
+            .Received(1)
+            .SendWelcomeEmailAsync(user);
+
+        await sutProvider.GetDependency<IReferenceEventService>()
+            .Received(1)
+            .RaiseEventAsync(Arg.Is<ReferenceEvent>(refEvent => refEvent.Type == ReferenceEventType.Signup));
+    }
+
+
+
+    [Theory]
+    [BitAutoData]
+    public async Task RegisterUserViaAcceptEmergencyAccessInviteToken_InvalidToken_ThrowsBadRequestException(SutProvider<RegisterUserCommand> sutProvider, User user,
+        string masterPasswordHash, EmergencyAccess emergencyAccess, string acceptEmergencyAccessInviteToken, Guid acceptEmergencyAccessId)
+    {
+        // Arrange
+        emergencyAccess.Email = "wrong@email.com";
+        emergencyAccess.Id = acceptEmergencyAccessId;
+
+        sutProvider.GetDependency<IDataProtectorTokenFactory<EmergencyAccessInviteTokenable>>()
+            .TryUnprotect(acceptEmergencyAccessInviteToken, out Arg.Any<EmergencyAccessInviteTokenable>())
+            .Returns(callInfo =>
+            {
+                callInfo[1] = new EmergencyAccessInviteTokenable(emergencyAccess, 10);
+                return true;
+            });
+
+        // Act & Assert
+        var result = await Assert.ThrowsAsync<BadRequestException>(() =>
+            sutProvider.Sut.RegisterUserViaAcceptEmergencyAccessInviteToken(user, masterPasswordHash, acceptEmergencyAccessInviteToken, acceptEmergencyAccessId));
+        Assert.Equal("Invalid accept emergency access invite token.", result.Message);
+
+    }
+
+    [Theory]
+    [BitAutoData]
+    public async Task RegisterUserViaAcceptEmergencyAccessInviteToken_DisabledOpenRegistration_ThrowsBadRequestException(SutProvider<RegisterUserCommand> sutProvider, User user,
+        string masterPasswordHash, string acceptEmergencyAccessInviteToken, Guid acceptEmergencyAccessId)
+    {
+        // Arrange
+        sutProvider.GetDependency<IGlobalSettings>()
+            .DisableUserRegistration = true;
+
+        // Act & Assert
+        var result = await Assert.ThrowsAsync<BadRequestException>(() =>
+            sutProvider.Sut.RegisterUserViaAcceptEmergencyAccessInviteToken(user, masterPasswordHash, acceptEmergencyAccessInviteToken, acceptEmergencyAccessId));
+        Assert.Equal("Open registration has been disabled by the system administrator.", result.Message);
     }
 
 
diff --git a/test/Identity.IntegrationTest/Controllers/AccountsControllerTests.cs b/test/Identity.IntegrationTest/Controllers/AccountsControllerTests.cs
index dcf2740c0..50f7d70ab 100644
--- a/test/Identity.IntegrationTest/Controllers/AccountsControllerTests.cs
+++ b/test/Identity.IntegrationTest/Controllers/AccountsControllerTests.cs
@@ -1,5 +1,6 @@
 using System.ComponentModel.DataAnnotations;
 using Bit.Core;
+using Bit.Core.Auth.Entities;
 using Bit.Core.Auth.Models.Api.Request.Accounts;
 using Bit.Core.Auth.Models.Business.Tokenables;
 using Bit.Core.Entities;
@@ -400,6 +401,75 @@ public class AccountsControllerTests : IClassFixture<IdentityApplicationFactory>
         Assert.Equal(kdfParallelism, user.KdfParallelism);
     }
 
+    [Theory, BitAutoData]
+    public async Task RegistrationWithEmailVerification_WithAcceptEmergencyAccessInviteToken_Succeeds(
+     [StringLength(1000)] string masterPasswordHash, [StringLength(50)] string masterPasswordHint, string userSymmetricKey,
+    KeysRequestModel userAsymmetricKeys, int kdfMemory, int kdfParallelism, EmergencyAccess emergencyAccess)
+    {
+
+        // Localize factory to just this test.
+        var localFactory = new IdentityApplicationFactory();
+
+        // Hardcoded, valid data
+        var email = "jsnider+local79813655659549@bitwarden.com";
+        var acceptEmergencyAccessInviteToken = "CfDJ8HFsgwUNr89EtnCal5H72cwjvdjWmBp3J0ry7KoG6zDFub-EeoA3cfLBXONq7thKq7QTBh6KJ--jU0Det7t3P9EXqxmEacxIlgFlBgtywIUho9N8nVQeNcltkQO9g0vj_ASshnn6fWK3zpqS6Z8JueVZ2TMtdks5uc7DjZurWFLX27Dpii-UusFD78Z5tCY-D79bkjHy43g1ULk2F2ZtwiJvp3C9QvXW1-12IEsyHHSxU-9RELe-_joo2iDIR-cvMmEfbEXK7uvuzNT2V0r22jalaAKFvd84Gza9Q0YSFn8z_nAJxVqEXsAVKdG8SRN5Wa3K2mdNoBMt20RrzNuuJhe6vzX0yP35HtC4e1YXXzWB";
+        var acceptEmergencyAccessId = new Guid("8bc5e574-cef6-4ee7-b9ed-b1e90158c016");
+
+        emergencyAccess.Id = acceptEmergencyAccessId;
+        emergencyAccess.Email = email;
+
+        var emergencyAccessInviteTokenable = new EmergencyAccessInviteTokenable(emergencyAccess, 10) { };
+
+        localFactory.SubstituteService<IDataProtectorTokenFactory<EmergencyAccessInviteTokenable>>(dataProtectorTokenFactory =>
+        {
+            dataProtectorTokenFactory.TryUnprotect(Arg.Is(acceptEmergencyAccessInviteToken), out Arg.Any<EmergencyAccessInviteTokenable>())
+                .Returns(callInfo =>
+                {
+                    callInfo[1] = emergencyAccessInviteTokenable;
+                    return true;
+                });
+        });
+
+
+        var registerFinishReqModel = new RegisterFinishRequestModel
+        {
+            Email = email,
+            MasterPasswordHash = masterPasswordHash,
+            MasterPasswordHint = masterPasswordHint,
+            AcceptEmergencyAccessInviteToken = acceptEmergencyAccessInviteToken,
+            AcceptEmergencyAccessId = acceptEmergencyAccessId,
+            Kdf = KdfType.PBKDF2_SHA256,
+            KdfIterations = AuthConstants.PBKDF2_ITERATIONS.Default,
+            UserSymmetricKey = userSymmetricKey,
+            UserAsymmetricKeys = userAsymmetricKeys,
+            KdfMemory = kdfMemory,
+            KdfParallelism = kdfParallelism
+        };
+
+        var postRegisterFinishHttpContext = await localFactory.PostRegisterFinishAsync(registerFinishReqModel);
+
+        Assert.Equal(StatusCodes.Status200OK, postRegisterFinishHttpContext.Response.StatusCode);
+
+        var database = localFactory.GetDatabaseContext();
+        var user = await database.Users
+            .SingleAsync(u => u.Email == email);
+
+        Assert.NotNull(user);
+
+        // Assert user properties match the request model
+        Assert.Equal(email, user.Email);
+        Assert.NotEqual(masterPasswordHash, user.MasterPassword);  // We execute server side hashing
+        Assert.NotNull(user.MasterPassword);
+        Assert.Equal(masterPasswordHint, user.MasterPasswordHint);
+        Assert.Equal(userSymmetricKey, user.Key);
+        Assert.Equal(userAsymmetricKeys.EncryptedPrivateKey, user.PrivateKey);
+        Assert.Equal(userAsymmetricKeys.PublicKey, user.PublicKey);
+        Assert.Equal(KdfType.PBKDF2_SHA256, user.Kdf);
+        Assert.Equal(AuthConstants.PBKDF2_ITERATIONS.Default, user.KdfIterations);
+        Assert.Equal(kdfMemory, user.KdfMemory);
+        Assert.Equal(kdfParallelism, user.KdfParallelism);
+    }
+
 
     [Theory, BitAutoData]
     public async Task PostRegisterVerificationEmailClicked_Success(