diff --git a/src/core/tests/Deal.Tests.Unit/Modules/Tenants/FakeInviteStore.cs b/src/core/tests/Deal.Tests.Unit/Modules/Tenants/FakeInviteStore.cs
deleted file mode 100644
index 8ec25bf..0000000
--- a/src/core/tests/Deal.Tests.Unit/Modules/Tenants/FakeInviteStore.cs
+++ /dev/null
@@ -1,84 +0,0 @@
-using Deal.Modules.Tenants.Application.Abstractions;
-using Deal.Modules.Tenants.Application.Models;
-
-namespace Deal.Tests.Unit.Modules.Tenants;
-
-/// <summary>
-/// In-memory реализация <see cref="IInviteStore"/> для юнит/HTTP-тестов приглашений.
-/// </summary>
-public class FakeInviteStore : IInviteStore
-{
-    private readonly List<InviteDto> _invites = [];
-    private readonly List<string> _calls = [];
-
-    /// <summary>
-    /// Приглашения хранилища в порядке добавления.
-    /// </summary>
-    public IReadOnlyList<InviteDto> Invites => _invites;
-
-    /// <summary>
-    /// Журнал мутирующих вызовов в порядке их совершения.
-    /// </summary>
-    public IReadOnlyList<string> Calls => _calls;
-
-    /// <summary>
-    /// Добавляет приглашение
-    /// </summary>
-    /// <param name="invite">Приглашение.</param>
-    public void AddInvite(InviteDto invite) => _invites.Add(invite);
-
-    /// <inheritdoc />
-    public Task CreateAsync(InviteDto invite, CancellationToken ct)
-    {
-        _invites.Add(invite);
-        _calls.Add($"create:{invite.Code}");
-        return Task.CompletedTask;
-    }
-
-    /// <inheritdoc />
-    public Task<InviteDto?> GetByCodeAsync(string code, CancellationToken ct) =>
-        Task.FromResult(_invites.SingleOrDefault(i => i.Code == code));
-
-    /// <inheritdoc />
-    public Task<IReadOnlyList<InviteDto>> ListAsync(CancellationToken ct) =>
-        Task.FromResult<IReadOnlyList<InviteDto>>(_invites.OrderByDescending(i => i.CreatedAt).ToList());
-
-    /// <inheritdoc />
-    public Task<bool> UpdateStatusAsync(
-        string code,
-        string status,
-        DateTimeOffset? activatedAt,
-        CancellationToken ct)
-    {
-        int index = _invites.FindIndex(i => i.Code == code);
-        if (index < 0)
-        {
-            return Task.FromResult(false);
-        }
-
-        _invites[index] = _invites[index] with { Status = status, ActivatedAt = activatedAt };
-        _calls.Add($"update:{code}:{status}");
-        return Task.FromResult(true);
-    }
-
-    /// <inheritdoc />
-    public virtual Task<bool> TryActivateAsync(
-        string code,
-        DateTimeOffset activatedAt,
-        CancellationToken ct)
-    {
-        int index = _invites.FindIndex(i => i.Code == code && i.Status == InviteStatuses.Pending);
-        if (index < 0)
-        {
-            return Task.FromResult(false);
-        }
-
-        _invites[index] = _invites[index] with { Status = InviteStatuses.Activated, ActivatedAt = activatedAt };
-        _calls.Add($"activate:{code}");
-        return Task.FromResult(true);
-    }
-
-    /// <inheritdoc />
-    public Task<InviteDto?> FindActiveByEmailAsync(string email, CancellationToken ct) =>
-        Task.FromResult(_invites.SingleOrDefault(i => i.Email == email && i.Status == InviteStatuses.Pending));
-}
diff --git a/src/core/tests/Deal.Tests.Unit/Modules/Tenants/InvitesServiceTests.cs b/src/core/tests/Deal.Tests.Unit/Modules/Tenants/InvitesServiceTests.cs
index 5b0d09a..e9371ae 100644
--- a/src/core/tests/Deal.Tests.Unit/Modules/Tenants/InvitesServiceTests.cs
+++ b/src/core/tests/Deal.Tests.Unit/Modules/Tenants/InvitesServiceTests.cs
@@ -1,4 +1,6 @@
 using Deal.Modules.Tenants.Application.Models;
+using Deal.Tests.Unit.Support;
+using NSubstitute;
 using Deal.Modules.Tenants.Application.Services;
 
 namespace Deal.Tests.Unit.Modules.Tenants;
@@ -19,8 +21,8 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task CreateInviteAsync_WithValidEmail_StoresPendingInviteWithSixteenCharCodeAndSeventyTwoHourExpiry()
     {
-        var store = new FakeInviteStore();
-        var service = new InvitesService(store);
+        var store = new TestInviteStore();
+        var service = new InvitesService(store.Store);
         var before = DateTimeOffset.UtcNow;
 
         var result = await service.CreateInviteAsync(OperatorId, "  New.User@Example.COM ", tenantId: null, CancellationToken.None);
@@ -46,7 +48,7 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task CreateInviteAsync_ForExistingTenant_KeepsTenantId()
     {
-        var service = new InvitesService(new FakeInviteStore());
+        var service = new InvitesService(new TestInviteStore().Store);
         var tenantId = Guid.NewGuid();
 
         var result = await service.CreateInviteAsync(OperatorId, FirstEmail, tenantId, CancellationToken.None);
@@ -59,8 +61,8 @@ public sealed class InvitesServiceTests
     [MemberData(nameof(InvalidEmails))]
     public async Task CreateInviteAsync_WithInvalidEmail_ReturnsInvalidEmailError(string? email)
     {
-        var store = new FakeInviteStore();
-        var service = new InvitesService(store);
+        var store = new TestInviteStore();
+        var service = new InvitesService(store.Store);
 
         var result = await service.CreateInviteAsync(OperatorId, email, tenantId: null, CancellationToken.None);
 
@@ -74,9 +76,9 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task CreateInviteAsync_WithDuplicatePendingEmail_ReturnsDuplicateActiveError()
     {
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(code: "existing-pending-code", email: FirstEmail, createdAt: DateTimeOffset.UtcNow.AddHours(-1)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         var result = await service.CreateInviteAsync(OperatorId, FirstEmail.ToUpperInvariant(), tenantId: null, CancellationToken.None);
 
@@ -90,10 +92,10 @@ public sealed class InvitesServiceTests
     {
         // Протухшее, но ещё не помеченное pending-приглашение не блокирует новый инвайт: сначала переводится
         // в expired (иначе partial unique-индекс invites.Email по pending не пустил бы новую строку), затем создаётся новый.
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         const string oldCode = "expired-pending-code";
         store.AddInvite(NewInvite(code: oldCode, email: FirstEmail, expiresAt: DateTimeOffset.UtcNow.AddHours(-1), createdAt: DateTimeOffset.UtcNow.AddDays(-4)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         var result = await service.CreateInviteAsync(OperatorId, FirstEmail, tenantId: null, CancellationToken.None);
 
@@ -106,9 +108,9 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task CreateInviteAsync_AfterRevokedInvite_AllowsNewInviteForSameEmail()
     {
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(code: "revoked-code", email: FirstEmail, status: InviteStatuses.Revoked, createdAt: DateTimeOffset.UtcNow.AddDays(-1)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         var result = await service.CreateInviteAsync(OperatorId, FirstEmail, tenantId: null, CancellationToken.None);
 
@@ -120,9 +122,9 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task RevokeAsync_WithPendingInvite_ChangesStatusToRevoked()
     {
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(code: "pending-code", email: FirstEmail, createdAt: DateTimeOffset.UtcNow.AddHours(-1)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         var result = await service.RevokeAsync("pending-code", CancellationToken.None);
 
@@ -135,7 +137,7 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task RevokeAsync_WithUnknownCode_ReturnsNotFoundError()
     {
-        var service = new InvitesService(new FakeInviteStore());
+        var service = new InvitesService(new TestInviteStore().Store);
 
         var result = await service.RevokeAsync("no-such-code", CancellationToken.None);
 
@@ -150,9 +152,9 @@ public sealed class InvitesServiceTests
     [InlineData(InviteStatuses.Expired)]
     public async Task RevokeAsync_WithNonPendingInvite_ReturnsNotPendingError(string status)
     {
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(code: "non-pending-code", email: FirstEmail, status: status, createdAt: DateTimeOffset.UtcNow.AddHours(-2)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         var result = await service.RevokeAsync("non-pending-code", CancellationToken.None);
 
@@ -165,9 +167,9 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task GetByCodeAsync_WhenPendingInviteExpired_MarksItExpiredAndReturnsExpiredStatus()
     {
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(code: "old-code", email: FirstEmail, expiresAt: DateTimeOffset.UtcNow.AddHours(-1), createdAt: DateTimeOffset.UtcNow.AddDays(-3)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         var invite = await service.GetByCodeAsync("old-code", CancellationToken.None);
 
@@ -180,9 +182,9 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task GetByCodeAsync_WithLivePendingInvite_ReturnsPendingWithoutStoreChange()
     {
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(code: "live-code", email: FirstEmail, createdAt: DateTimeOffset.UtcNow.AddHours(-1)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         var invite = await service.GetByCodeAsync("live-code", CancellationToken.None);
 
@@ -194,7 +196,7 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task GetByCodeAsync_WithUnknownCode_ReturnsNull()
     {
-        var service = new InvitesService(new FakeInviteStore());
+        var service = new InvitesService(new TestInviteStore().Store);
 
         Assert.Null(await service.GetByCodeAsync("no-such-code", CancellationToken.None));
     }
@@ -203,11 +205,11 @@ public sealed class InvitesServiceTests
     public async Task ListAsync_ReturnsNewestFirstAndMarksExpiredPendingInvites()
     {
         // expired проставляется и в списке (лениво при чтении), чтобы оператор видел фактический статус.
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(code: "expired-pending", email: FirstEmail, expiresAt: DateTimeOffset.UtcNow.AddHours(-1), createdAt: DateTimeOffset.UtcNow.AddDays(-3)));
         store.AddInvite(NewInvite(code: "live-pending", email: SecondEmail, createdAt: DateTimeOffset.UtcNow.AddDays(-1)));
         store.AddInvite(NewInvite(code: "revoked", email: "revoked@example.com", status: InviteStatuses.Revoked, createdAt: DateTimeOffset.UtcNow.AddHours(-1)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         IReadOnlyList<InviteDto> items = await service.ListAsync(CancellationToken.None);
 
@@ -221,9 +223,9 @@ public sealed class InvitesServiceTests
     [Fact]
     public async Task ListAsync_WithExpiredNonPendingRows_DoesNotTouchThem()
     {
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(code: "activated-old", email: FirstEmail, status: InviteStatuses.Activated, expiresAt: DateTimeOffset.UtcNow.AddHours(-5), createdAt: DateTimeOffset.UtcNow.AddDays(-2)));
-        var service = new InvitesService(store);
+        var service = new InvitesService(store.Store);
 
         IReadOnlyList<InviteDto> items = await service.ListAsync(CancellationToken.None);
 
diff --git a/src/core/tests/Deal.Tests.Unit/Modules/Tenants/JoinFlowTests.cs b/src/core/tests/Deal.Tests.Unit/Modules/Tenants/JoinFlowTests.cs
index 848f194..782caf6 100644
--- a/src/core/tests/Deal.Tests.Unit/Modules/Tenants/JoinFlowTests.cs
+++ b/src/core/tests/Deal.Tests.Unit/Modules/Tenants/JoinFlowTests.cs
@@ -25,7 +25,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WithNewTenant_ReturnsOkAndCreatesUserTenantAndActivatedInvite()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null));
         var provisioner = new TestTenantProvisioner();
         var tenantStore = new FakeTenantStore();
@@ -67,7 +67,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WithNewTenantAndEmptyName_UsesEmailAsTenantName()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null));
         var tenantStore = new FakeTenantStore();
         var service = NewService(inviteStore, tenantStore, new TestTenantProvisioner().Provisioner, new FakeAuthStore(), TestHashers.New());
@@ -82,7 +82,7 @@ public sealed class JoinFlowTests
     public async Task ActivateAsync_WithExistingTenant_JoinsTenantWithoutProvisioning()
     {
         var tenantId = Guid.NewGuid();
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: tenantId));
         var provisioner = new TestTenantProvisioner();
         // Активный тенант уже существует (создан оператором ранее) — join присоединяется к нему.
@@ -105,7 +105,7 @@ public sealed class JoinFlowTests
     public async Task ActivateAsync_WithMissingTenant_ReturnsTenantNotFoundWithoutSideEffects()
     {
         var tenantId = Guid.NewGuid();
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: tenantId));
         var tenantStore = new FakeTenantStore(); // целевого тенанта в реестре нет — «битый» инвайт
         var authStore = new FakeAuthStore();
@@ -123,7 +123,7 @@ public sealed class JoinFlowTests
     public async Task ActivateAsync_WithSuspendedTenant_ReturnsTenantSuspendedWithoutSideEffects()
     {
         var tenantId = Guid.NewGuid();
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: tenantId));
         var tenantStore = new FakeTenantStore(new TenantRecordDto(tenantId, "Suspended", TenantStatuses.Suspended, DateTimeOffset.UtcNow));
         var authStore = new FakeAuthStore();
@@ -140,7 +140,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WithUnknownCode_ReturnsNotFoundWithoutSideEffects()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         var tenantStore = new FakeTenantStore();
         var authStore = new FakeAuthStore();
         var service = NewService(inviteStore, tenantStore, new TestTenantProvisioner().Provisioner, authStore, TestHashers.New());
@@ -156,7 +156,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WithExpiredPendingInvite_ReturnsExpiredAndPersistsTransition()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null, expiresAt: DateTimeOffset.UtcNow.AddHours(-1)));
         var tenantStore = new FakeTenantStore();
         var authStore = new FakeAuthStore();
@@ -174,7 +174,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WithActivatedInvite_ReturnsUsed()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null, status: InviteStatuses.Activated));
         var service = NewService(inviteStore, new FakeTenantStore(), new TestTenantProvisioner().Provisioner, new FakeAuthStore(), TestHashers.New());
 
@@ -187,7 +187,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WithRevokedInvite_ReturnsRevoked()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null, status: InviteStatuses.Revoked));
         var service = NewService(inviteStore, new FakeTenantStore(), new TestTenantProvisioner().Provisioner, new FakeAuthStore(), TestHashers.New());
 
@@ -200,7 +200,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WithMismatchedEmail_ReturnsEmailMismatchAndKeepsInvitePending()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null));
         var tenantStore = new FakeTenantStore();
         var authStore = new FakeAuthStore();
@@ -218,7 +218,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WithTakenEmail_ReturnsEmailTakenAndKeepsInvitePending()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null));
         var tenantStore = new FakeTenantStore();
         var authStore = new FakeAuthStore();
@@ -245,7 +245,7 @@ public sealed class JoinFlowTests
     [InlineData("123")]
     public async Task ActivateAsync_WithShortPassword_ReturnsPasswordTooShort(string? password)
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null));
         var tenantStore = new FakeTenantStore();
         var authStore = new FakeAuthStore();
@@ -263,7 +263,7 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_SecondActivationWithSameCode_ReturnsUsedWithoutDuplicates()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null));
         var provisioner = new TestTenantProvisioner();
         var tenantStore = new FakeTenantStore();
@@ -284,8 +284,9 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task ActivateAsync_WhenParallelRevokeWinsBeforeCas_ReturnsRevokedWithoutSideEffects()
     {
-        var inviteStore = new RacingInviteStore(statusBeforeActivate: InviteStatuses.Revoked);
-        inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null));
+        var inviteStore = new TestInviteStore();
+        // Конкурент (отзыв) «успел» до нашего CAS — приглашение уже отозвано, активация не выполнится.
+        inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null, status: InviteStatuses.Revoked));
         var tenantStore = new FakeTenantStore();
         var authStore = new FakeAuthStore();
         var provisioner = new TestTenantProvisioner();
@@ -306,8 +307,9 @@ public sealed class JoinFlowTests
     {
         // Гонка двух активаций одного кода: победила параллельная (уже activated к моменту нашего CAS) —
         // проигравшая отвечает «уже использовано» и ничего не создаёт.
-        var inviteStore = new RacingInviteStore(statusBeforeActivate: InviteStatuses.Activated);
-        inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null));
+        var inviteStore = new TestInviteStore();
+        // Конкурентная активация «успела» до нашего CAS — приглашение уже активировано.
+        inviteStore.AddInvite(NewInvite(Code, Email, tenantId: null, status: InviteStatuses.Activated));
         var tenantStore = new FakeTenantStore();
         var authStore = new FakeAuthStore();
         var provisioner = new TestTenantProvisioner();
@@ -327,11 +329,11 @@ public sealed class JoinFlowTests
     public async Task TryActivateAsync_AfterRevoke_RefusesTransitionAndKeepsRevoked()
     {
         // Контракт CAS на уровне хранилища: условный переход не перезаписывает параллельный revoke.
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
         store.AddInvite(NewInvite(Code, Email, tenantId: null));
-        await store.UpdateStatusAsync(Code, InviteStatuses.Revoked, null, CancellationToken.None);
+        await store.Store.UpdateStatusAsync(Code, InviteStatuses.Revoked, null, CancellationToken.None);
 
-        bool activated = await store.TryActivateAsync(Code, DateTimeOffset.UtcNow, CancellationToken.None);
+        bool activated = await store.Store.TryActivateAsync(Code, DateTimeOffset.UtcNow, CancellationToken.None);
 
         Assert.False(activated);
         InviteDto invite = Assert.Single(store.Invites);
@@ -342,9 +344,9 @@ public sealed class JoinFlowTests
     [Fact]
     public async Task TryActivateAsync_WithUnknownCode_ReturnsFalse()
     {
-        var store = new FakeInviteStore();
+        var store = new TestInviteStore();
 
-        bool activated = await store.TryActivateAsync(WrongCode, DateTimeOffset.UtcNow, CancellationToken.None);
+        bool activated = await store.Store.TryActivateAsync(WrongCode, DateTimeOffset.UtcNow, CancellationToken.None);
 
         Assert.False(activated);
     }
@@ -353,13 +355,13 @@ public sealed class JoinFlowTests
 
     // Собирает JoinService на общих фейк-хранилищах (все состояния — свежие).
     private static JoinService NewService(
-        FakeInviteStore inviteStore,
+        TestInviteStore inviteStore,
         FakeTenantStore tenantStore,
         ITenantProvisioner provisioner,
         FakeAuthStore authStore,
         IPasswordHasher passwordHasher) =>
         new(
-            new InvitesService(inviteStore),
+            new InvitesService(inviteStore.Store),
             new TenantService(tenantStore, provisioner),
             authStore,
             passwordHasher,
@@ -382,17 +384,5 @@ public sealed class JoinFlowTests
             CreatedById: Guid.NewGuid(),
             DateTimeOffset.UtcNow);
 
-    // FakeInviteStore, имитирующий гонку: к моменту CAS-вызова конкурент уже перевёл строку в заданный статус.
-    private sealed class RacingInviteStore(string statusBeforeActivate) : FakeInviteStore
-    {
-        public override Task<bool> TryActivateAsync(
-            string code,
-            DateTimeOffset activatedAt,
-            CancellationToken ct)
-        {
-            // Конкурент (отзыв/другая активация) «успел» до нашего CAS — активация обязана не выполниться.
-            _ = base.UpdateStatusAsync(code, statusBeforeActivate, null, ct);
-            return base.TryActivateAsync(code, activatedAt, ct);
-        }
-    }
+    // TestInviteStore, имитирующий гонку: к моменту CAS-вызова конкурент уже перевёл строку в заданный статус.
 }
diff --git a/src/core/tests/Deal.Tests.Unit/Support/JoinEndpointHttpTests.cs b/src/core/tests/Deal.Tests.Unit/Support/JoinEndpointHttpTests.cs
index 94b5b55..e6f5d51 100644
--- a/src/core/tests/Deal.Tests.Unit/Support/JoinEndpointHttpTests.cs
+++ b/src/core/tests/Deal.Tests.Unit/Support/JoinEndpointHttpTests.cs
@@ -35,7 +35,7 @@ public sealed class JoinEndpointHttpTests
     [Fact]
     public async Task Join_WithValidPendingInvite_ReturnsOkCreatesUserAndWritesAudit()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Email));
         var authStore = new FakeAuthStore();
         var tenantStore = new FakeTenantStore();
@@ -78,7 +78,7 @@ public sealed class JoinEndpointHttpTests
     [Fact]
     public async Task Join_WithSameCodeTwice_SecondReturns400AlreadyUsed()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Email));
         var authStore = new FakeAuthStore();
 
@@ -106,7 +106,7 @@ public sealed class JoinEndpointHttpTests
     [Fact]
     public async Task Join_WithMismatchedEmail_Returns400EmailMismatchAndKeepsInvite()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Email));
         var authStore = new FakeAuthStore();
 
@@ -128,7 +128,7 @@ public sealed class JoinEndpointHttpTests
     [Fact]
     public async Task Join_WithRevokedInvite_Returns400Revoked()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Email, status: InviteStatuses.Revoked));
 
         await RunAsync(
@@ -146,7 +146,7 @@ public sealed class JoinEndpointHttpTests
     [Fact]
     public async Task Join_WithExpiredInvite_Returns400Expired()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Email, expiresAt: DateTimeOffset.UtcNow.AddHours(-1)));
 
         await RunAsync(
@@ -165,7 +165,7 @@ public sealed class JoinEndpointHttpTests
     public async Task Join_WithUnknownCode_Returns400NotFound()
     {
         await RunAsync(
-            new FakeInviteStore(), new FakeTenantStore(), new TestTenantProvisioner().Provisioner, new FakeAuthStore(), new FakeAuditLogStore(),
+            new TestInviteStore(), new FakeTenantStore(), new TestTenantProvisioner().Provisioner, new FakeAuthStore(), new FakeAuditLogStore(),
             async (baseAddress, client) =>
             {
                 using HttpResponseMessage response = await PostJsonAsync(
@@ -179,7 +179,7 @@ public sealed class JoinEndpointHttpTests
     [Fact]
     public async Task Join_WithShortPassword_Returns400PasswordTooShort()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Email));
 
         await RunAsync(
@@ -199,7 +199,7 @@ public sealed class JoinEndpointHttpTests
     [Fact]
     public async Task Join_WithTakenEmail_Returns400EmailAlreadyRegistered()
     {
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Email));
         var authStore = new FakeAuthStore();
         authStore.AddUser(new StoredUserDto(Guid.NewGuid(), Email, TenantId: Guid.NewGuid(), Status: "active", "hash"));
@@ -223,7 +223,7 @@ public sealed class JoinEndpointHttpTests
     public async Task Join_ExistingTenantInvite_JoinsTenantWithoutCreatingNewOne()
     {
         var tenantId = Guid.NewGuid();
-        var inviteStore = new FakeInviteStore();
+        var inviteStore = new TestInviteStore();
         inviteStore.AddInvite(NewInvite(Email, tenantId: tenantId));
         // Активный тенант уже существует (создан оператором ранее) — join присоединяется к нему.
         var tenantStore = new FakeTenantStore(new TenantRecordDto(tenantId, "Existing", TenantStatuses.Active, DateTimeOffset.UtcNow));
@@ -249,7 +249,7 @@ public sealed class JoinEndpointHttpTests
 
     // Поднимает in-process Kestrel с /api/join на фейк-хранилищах и прогоняет сценарий.
     private static async Task RunAsync(
-        FakeInviteStore inviteStore,
+        TestInviteStore inviteStore,
         FakeTenantStore tenantStore,
         ITenantProvisioner provisioner,
         FakeAuthStore authStore,
@@ -266,7 +266,7 @@ public sealed class JoinEndpointHttpTests
         builder.Services.AddSingleton(TestHashers.New());
         builder.Services.AddSingleton<IAuthStore>(authStore);
         builder.Services.AddSingleton<IAuditLogStore>(auditStore);
-        builder.Services.AddSingleton<IInviteStore>(inviteStore);
+        builder.Services.AddSingleton<IInviteStore>(inviteStore.Store);
         builder.Services.AddSingleton<ITenantRepository>(tenantStore);
         builder.Services.AddSingleton<ITenantProvisioner>(provisioner);
 
diff --git a/src/core/tests/Deal.Tests.Unit/Support/OperatorAuthHttpHost.cs b/src/core/tests/Deal.Tests.Unit/Support/OperatorAuthHttpHost.cs
index 3c3932f..9be025c 100644
--- a/src/core/tests/Deal.Tests.Unit/Support/OperatorAuthHttpHost.cs
+++ b/src/core/tests/Deal.Tests.Unit/Support/OperatorAuthHttpHost.cs
@@ -64,9 +64,9 @@ internal static class OperatorAuthHttpHost
     public static async Task RunAsync(
         FakeOperatorAuthStore operatorStore,
         FakeAuthStore userStore,
-        Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeInviteStore, FakeAuditLogStore, Task> scenario,
+        Func<string, FakeOperatorAuthStore, FakeAuthStore, TestInviteStore, FakeAuditLogStore, Task> scenario,
         FakeAuditLogStore? auditStore = null,
-        FakeInviteStore? inviteStore = null) =>
+        TestInviteStore? inviteStore = null) =>
         await RunCoreAsync(
             operatorStore,
             userStore,
@@ -88,9 +88,9 @@ internal static class OperatorAuthHttpHost
     public static async Task RunAsync(
         FakeOperatorAuthStore operatorStore,
         FakeAuthStore userStore,
-        Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, FakeInviteStore, FakeAuditLogStore, Task> scenario,
+        Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, TestInviteStore, FakeAuditLogStore, Task> scenario,
         FakeAuditLogStore? auditStore = null,
-        FakeInviteStore? inviteStore = null,
+        TestInviteStore? inviteStore = null,
         FakeTenantStore? tenantStore = null) =>
         await RunCoreAsync(
             operatorStore,
@@ -115,9 +115,9 @@ internal static class OperatorAuthHttpHost
     public static async Task RunAsync(
         FakeOperatorAuthStore operatorStore,
         FakeAuthStore userStore,
-        Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, FakeInviteStore, FakeAuditLogStore, FakeTenantLimitStore, Task> scenario,
+        Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, TestInviteStore, FakeAuditLogStore, FakeTenantLimitStore, Task> scenario,
         FakeAuditLogStore? auditStore = null,
-        FakeInviteStore? inviteStore = null,
+        TestInviteStore? inviteStore = null,
         FakeTenantStore? tenantStore = null,
         FakeTenantLimitStore? limitStore = null,
         RateLimitOptions? rateLimitOptions = null,
@@ -162,16 +162,16 @@ internal static class OperatorAuthHttpHost
         FakeOperatorAuthStore operatorStore,
         FakeAuthStore userStore,
         FakeAuditLogStore? auditStore,
-        FakeInviteStore? inviteStore,
+        TestInviteStore? inviteStore,
         FakeTenantStore? tenantStore,
         FakeTenantLimitStore? limitStore,
-        Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, FakeInviteStore, FakeAuditLogStore, FakeTenantLimitStore, TestGlobalSettingsStore, Task> scenario,
+        Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, TestInviteStore, FakeAuditLogStore, FakeTenantLimitStore, TestGlobalSettingsStore, Task> scenario,
         RateLimitOptions? rateLimitOptions = null,
         FakeTokenUsageEventStore? tokenUsageStore = null,
         TestGlobalSettingsStore? globalSettingsStore = null)
     {
         FakeAuditLogStore effectiveAuditStore = auditStore ?? new FakeAuditLogStore();
-        FakeInviteStore effectiveInviteStore = inviteStore ?? new FakeInviteStore();
+        TestInviteStore effectiveInviteStore = inviteStore ?? new TestInviteStore();
         FakeTenantStore effectiveTenantStore = tenantStore ?? new FakeTenantStore();
         FakeTenantLimitStore effectiveLimitStore = limitStore ?? new FakeTenantLimitStore();
         FakeTokenUsageEventStore effectiveTokenUsageStore = tokenUsageStore ?? new FakeTokenUsageEventStore();
@@ -189,7 +189,7 @@ internal static class OperatorAuthHttpHost
         builder.Services.AddSingleton<IAuthStore>(userStore);
         builder.Services.AddSingleton<IOperatorAuthStore>(operatorStore);
         builder.Services.AddSingleton<IAuditLogStore>(effectiveAuditStore);
-        builder.Services.AddSingleton<IInviteStore>(effectiveInviteStore);
+        builder.Services.AddSingleton<IInviteStore>(effectiveInviteStore.Store);
         builder.Services.AddSingleton<ITenantRepository>(effectiveTenantStore);
         builder.Services.AddSingleton<ITenantLimitStore>(effectiveLimitStore);
         builder.Services.AddSingleton<IGlobalSettingsStore>(effectiveGlobalSettingsStore.Store);
diff --git a/src/core/tests/Deal.Tests.Unit/Support/OperatorHealthEndpointsHttpTests.cs b/src/core/tests/Deal.Tests.Unit/Support/OperatorHealthEndpointsHttpTests.cs
index 9665900..1eaad3f 100644
--- a/src/core/tests/Deal.Tests.Unit/Support/OperatorHealthEndpointsHttpTests.cs
+++ b/src/core/tests/Deal.Tests.Unit/Support/OperatorHealthEndpointsHttpTests.cs
@@ -92,7 +92,7 @@ public sealed class OperatorHealthEndpointsHttpTests
     }
 
     // Прогоняет сценарий на хосте с активным оператором operator/operator (реестр/лимиты пустые).
-    private static Task RunAsync(Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, FakeInviteStore, FakeAuditLogStore, FakeTenantLimitStore, Task> scenario) =>
+    private static Task RunAsync(Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, TestInviteStore, FakeAuditLogStore, FakeTenantLimitStore, Task> scenario) =>
         OperatorAuthHttpHost.RunAsync(NewOperatorStore(), new FakeAuthStore(), scenario);
 
     // Фейк-хранилище оператора с активным оператором operator/operator.
diff --git a/src/core/tests/Deal.Tests.Unit/Support/OperatorLimitsEndpointsHttpTests.cs b/src/core/tests/Deal.Tests.Unit/Support/OperatorLimitsEndpointsHttpTests.cs
index 7fe32cb..ad954d0 100644
--- a/src/core/tests/Deal.Tests.Unit/Support/OperatorLimitsEndpointsHttpTests.cs
+++ b/src/core/tests/Deal.Tests.Unit/Support/OperatorLimitsEndpointsHttpTests.cs
@@ -284,7 +284,7 @@ public sealed class OperatorLimitsEndpointsHttpTests
         $"{baseAddress}/api/operator/tenants/{tenantId}/limit";
 
     // Прогоняет сценарий на хосте с двумя активными тенантами и предзаполненными строками лимитов.
-    private static Task RunAsync(Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, FakeInviteStore, FakeAuditLogStore, FakeTenantLimitStore, Task> scenario, FakeAuditLogStore? auditStore = null)
+    private static Task RunAsync(Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, TestInviteStore, FakeAuditLogStore, FakeTenantLimitStore, Task> scenario, FakeAuditLogStore? auditStore = null)
     {
         // Первый тенант: расход 80% месячного бюджета (8 000 000 / 10 000 000) + флаг Warned80;
         // второй: небольшой бюджет без расхода. Дата начала периода — текущая (reset не срабатывает).
diff --git a/src/core/tests/Deal.Tests.Unit/Support/OperatorMaintenanceEndpointsHttpTests.cs b/src/core/tests/Deal.Tests.Unit/Support/OperatorMaintenanceEndpointsHttpTests.cs
index ea573c7..ccd0d79 100644
--- a/src/core/tests/Deal.Tests.Unit/Support/OperatorMaintenanceEndpointsHttpTests.cs
+++ b/src/core/tests/Deal.Tests.Unit/Support/OperatorMaintenanceEndpointsHttpTests.cs
@@ -72,7 +72,7 @@ public sealed class OperatorMaintenanceEndpointsHttpTests
     }
 
     // Прогоняет сценарий на хосте с активным оператором operator/operator и заданным реестром тенантов.
-    private static Task RunAsync(FakeTenantStore tenantStore, Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, FakeInviteStore, FakeAuditLogStore, Task> scenario) =>
+    private static Task RunAsync(FakeTenantStore tenantStore, Func<string, FakeOperatorAuthStore, FakeAuthStore, FakeTenantStore, TestInviteStore, FakeAuditLogStore, Task> scenario) =>
         OperatorAuthHttpHost.RunAsync(NewOperatorStore(), new FakeAuthStore(), scenario, tenantStore: tenantStore);
 
     // Фейк-хранилище оператора с активным оператором operator/operator.
diff --git a/src/core/tests/Deal.Tests.Unit/Support/TestInviteStore.cs b/src/core/tests/Deal.Tests.Unit/Support/TestInviteStore.cs
new file mode 100644
index 0000000..bdf8c82
--- /dev/null
+++ b/src/core/tests/Deal.Tests.Unit/Support/TestInviteStore.cs
@@ -0,0 +1,94 @@
+using Deal.Modules.Tenants.Application.Abstractions;
+using Deal.Modules.Tenants.Application.Models;
+using NSubstitute;
+
+namespace Deal.Tests.Unit.Support;
+
+/// <summary>
+/// Подставка <see cref="IInviteStore"/> на списках: сервисы получают NSubstitute-подставку
+/// (<see cref="Store"/>), тесты сеют приглашения через <see cref="AddInvite"/> и проверяют
+/// состояние через <see cref="Invites"/> и <see cref="Calls"/>.
+/// </summary>
+public class TestInviteStore
+{
+    private readonly List<InviteDto> _invites = [];
+    private readonly List<string> _calls = [];
+
+    /// <summary>
+    /// Подставка порта приглашений (создаётся в конструкторе).
+    /// </summary>
+    public IInviteStore Store { get; }
+
+    /// <summary>
+    /// Приглашения хранилища в порядке добавления.
+    /// </summary>
+    public IReadOnlyList<InviteDto> Invites => _invites;
+
+    /// <summary>
+    /// Журнал мутирующих вызовов в порядке их совершения.
+    /// </summary>
+    public IReadOnlyList<string> Calls => _calls;
+
+    /// <summary>
+    /// Создаёт подставку с пустым хранилищем.
+    /// </summary>
+    public TestInviteStore()
+    {
+        Store = Substitute.For<IInviteStore>();
+        Store.When(s => s.CreateAsync(Arg.Any<InviteDto>(), Arg.Any<CancellationToken>()))
+            .Do(ci =>
+            {
+                InviteDto invite = ci.Arg<InviteDto>();
+                _invites.Add(invite);
+                _calls.Add($"create:{invite.Code}");
+            });
+        Store.GetByCodeAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(ci => _invites.SingleOrDefault(i => i.Code == ci.ArgAt<string>(0)));
+        Store.ListAsync(Arg.Any<CancellationToken>())
+            .Returns(ci => _invites.OrderByDescending(i => i.CreatedAt).ToList());
+        Store.UpdateStatusAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<DateTimeOffset?>(), Arg.Any<CancellationToken>())
+            .Returns(ci =>
+            {
+                int index = _invites.FindIndex(i => i.Code == ci.ArgAt<string>(0));
+                if (index < 0)
+                {
+                    return false;
+                }
+
+                _invites[index] = _invites[index] with
+                {
+                    Status = ci.ArgAt<string>(1),
+                    ActivatedAt = ci.ArgAt<DateTimeOffset?>(2),
+                };
+                _calls.Add($"update:{ci.ArgAt<string>(0)}:{ci.ArgAt<string>(1)}");
+                return true;
+            });
+        Store.TryActivateAsync(Arg.Any<string>(), Arg.Any<DateTimeOffset>(), Arg.Any<CancellationToken>())
+            .Returns(ci =>
+            {
+                int index = _invites.FindIndex(i =>
+                    i.Code == ci.ArgAt<string>(0) && i.Status == InviteStatuses.Pending);
+                if (index < 0)
+                {
+                    return false;
+                }
+
+                _invites[index] = _invites[index] with
+                {
+                    Status = InviteStatuses.Activated,
+                    ActivatedAt = ci.ArgAt<DateTimeOffset>(1),
+                };
+                _calls.Add($"activate:{ci.ArgAt<string>(0)}");
+                return true;
+            });
+        Store.FindActiveByEmailAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(ci => _invites.SingleOrDefault(i =>
+                i.Email == ci.ArgAt<string>(0) && i.Status == InviteStatuses.Pending));
+    }
+
+    /// <summary>
+    /// Добавляет приглашение
+    /// </summary>
+    /// <param name="invite">Приглашение.</param>
+    public void AddInvite(InviteDto invite) => _invites.Add(invite);
+}