diff --git a/services/apps/alcs/src/alcs/notice-of-intent/notice-of-intent-tag/notice-of-intent-tag.controller.spec.ts b/services/apps/alcs/src/alcs/notice-of-intent/notice-of-intent-tag/notice-of-intent-tag.controller.spec.ts
index 1c998ad9c..fb2d59f16 100644
--- a/services/apps/alcs/src/alcs/notice-of-intent/notice-of-intent-tag/notice-of-intent-tag.controller.spec.ts
+++ b/services/apps/alcs/src/alcs/notice-of-intent/notice-of-intent-tag/notice-of-intent-tag.controller.spec.ts
@@ -1,19 +1,31 @@
 import { Test, TestingModule } from '@nestjs/testing';
 import { NoticeOfIntentTagController } from './notice-of-intent-tag.controller';
 import { NoticeOfIntentTagService } from './notice-of-intent-tag.service';
-import { DeepMocked } from '@golevelup/nestjs-testing';
+import { createMock, DeepMocked } from '@golevelup/nestjs-testing';
 import { ClsService } from 'nestjs-cls';
 import { mockKeyCloakProviders } from '../../../../test/mocks/mockTypes';
+import {
+  initNoticeOfIntentMockEntity,
+  initNoticeOfIntentWithTagsMockEntity,
+  initTagMockEntity,
+} from '../../../../test/mocks/mockEntities';
+import { NoticeOfIntentTagDto } from './notice-of-intent-tag.dto';
 
 describe('NoticeOfIntentTagController', () => {
   let controller: NoticeOfIntentTagController;
-  let tagService: DeepMocked<NoticeOfIntentTagService>;
+  let noiTagService: DeepMocked<NoticeOfIntentTagService>;
+
+  const mockNoticeOfIntentEntityWithoutTags = initNoticeOfIntentMockEntity();
+  mockNoticeOfIntentEntityWithoutTags.tags = [];
+  const mockNoticeOfIntentEntityWithTags = initNoticeOfIntentWithTagsMockEntity();
+  const mockTagEntity = initTagMockEntity();
 
   beforeEach(async () => {
+    noiTagService = createMock();
     const module: TestingModule = await Test.createTestingModule({
       controllers: [NoticeOfIntentTagController],
       providers: [
-        { provide: NoticeOfIntentTagService, useValue: tagService },
+        { provide: NoticeOfIntentTagService, useValue: noiTagService },
         {
           provide: ClsService,
           useValue: {},
@@ -28,4 +40,31 @@ describe('NoticeOfIntentTagController', () => {
   it('should be defined', () => {
     expect(controller).toBeDefined();
   });
+
+  it('should return tags for the noi', async () => {
+    noiTagService.getNoticeOfIntentTags.mockResolvedValue([mockTagEntity]);
+
+    const result = await controller.getApplicationTags('noi_1');
+    expect(noiTagService.getNoticeOfIntentTags).toHaveBeenCalledTimes(1);
+    expect(result[0].name).toEqual('tag-name');
+  });
+
+  it('should create tags', async () => {
+    noiTagService.addTagToNoticeOfIntent.mockResolvedValue(mockNoticeOfIntentEntityWithTags);
+
+    const mockTagDto = new NoticeOfIntentTagDto();
+    mockTagDto.tagName = 'tag-name';
+
+    const result = await controller.addTagToApplication('noi_1', mockTagDto);
+    expect(noiTagService.addTagToNoticeOfIntent).toHaveBeenCalledTimes(1);
+    expect(result.tags[0].name).toEqual('tag-name');
+  });
+
+  it('should remove tags', async () => {
+    noiTagService.removeTagFromNoticeOfIntent.mockResolvedValue(mockNoticeOfIntentEntityWithoutTags);
+
+    const result = await controller.removeTagFromApplication('noi_1', 'tag-name');
+    expect(noiTagService.removeTagFromNoticeOfIntent).toHaveBeenCalledTimes(1);
+    expect(result.tags.length).toEqual(0);
+  });
 });
diff --git a/services/apps/alcs/src/alcs/notice-of-intent/notice-of-intent-tag/notice-of-intent-tag.service.spec.ts b/services/apps/alcs/src/alcs/notice-of-intent/notice-of-intent-tag/notice-of-intent-tag.service.spec.ts
index f03153fc7..5e50ecc0a 100644
--- a/services/apps/alcs/src/alcs/notice-of-intent/notice-of-intent-tag/notice-of-intent-tag.service.spec.ts
+++ b/services/apps/alcs/src/alcs/notice-of-intent/notice-of-intent-tag/notice-of-intent-tag.service.spec.ts
@@ -5,24 +5,42 @@ import { NoticeOfIntent } from '../notice-of-intent.entity';
 import { createMock, DeepMocked } from '@golevelup/nestjs-testing';
 import { Repository } from 'typeorm';
 import { Tag } from '../../tag/tag.entity';
+import {
+  initNoticeOfIntentMockEntity,
+  initNoticeOfIntentWithTagsMockEntity,
+  initTagMockEntity,
+} from '../../../../test/mocks/mockEntities';
+import { ServiceNotFoundException, ServiceValidationException } from '@app/common/exceptions/base.exception';
 
 describe('NoticeOfIntentTagService', () => {
   let service: NoticeOfIntentTagService;
-  let noiRepository: DeepMocked<Repository<NoticeOfIntent>>;
-  let tagRepository: DeepMocked<Repository<Tag>>;
+  let noiRepositoryMock: DeepMocked<Repository<NoticeOfIntent>>;
+  let tagRepositoryMock: DeepMocked<Repository<Tag>>;
+
+  let mockNoiEntityWithoutTags: NoticeOfIntent;
+  let mockNoiEntityWithTags: NoticeOfIntent;
+  let mockNoiEntityWithDifferentTags: NoticeOfIntent;
+  let mockTagEntity: Tag;
 
   beforeEach(async () => {
-    noiRepository = createMock();
+    tagRepositoryMock = createMock();
+    noiRepositoryMock = createMock();
+    mockNoiEntityWithoutTags = initNoticeOfIntentMockEntity();
+    mockNoiEntityWithTags = initNoticeOfIntentWithTagsMockEntity();
+    mockNoiEntityWithDifferentTags = initNoticeOfIntentWithTagsMockEntity();
+    mockNoiEntityWithDifferentTags.tags[0].name = 'tag-name-2';
+    mockNoiEntityWithDifferentTags.tags[0].uuid = 'tag-uuid-2';
+    mockTagEntity = initTagMockEntity();
     const module: TestingModule = await Test.createTestingModule({
       providers: [
         NoticeOfIntentTagService,
         {
           provide: getRepositoryToken(NoticeOfIntent),
-          useValue: noiRepository,
+          useValue: noiRepositoryMock,
         },
         {
           provide: getRepositoryToken(Tag),
-          useValue: tagRepository,
+          useValue: tagRepositoryMock,
         },
       ],
     }).compile();
@@ -33,4 +51,75 @@ describe('NoticeOfIntentTagService', () => {
   it('should be defined', () => {
     expect(service).toBeDefined();
   });
+
+  it('should add tag to the noi if not existing', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(mockNoiEntityWithoutTags);
+    tagRepositoryMock.findOne.mockResolvedValue(mockTagEntity);
+    noiRepositoryMock.save.mockResolvedValue(mockNoiEntityWithTags);
+
+    await service.addTagToNoticeOfIntent('app_1', 'tag-name');
+    expect(mockNoiEntityWithoutTags.tags.length).toEqual(1);
+    expect(noiRepositoryMock.save).toHaveBeenCalledTimes(1);
+  });
+
+  it('should raise an error if noi is not found', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(null);
+
+    await expect(service.addTagToNoticeOfIntent('noi-1', 'tag-name')).rejects.toThrow(ServiceNotFoundException);
+  });
+
+  it('should throw an error if tag is not found', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(mockNoiEntityWithoutTags);
+    tagRepositoryMock.findOne.mockResolvedValue(null);
+
+    await expect(service.addTagToNoticeOfIntent('noi-1', 'tag-name')).rejects.toThrow(ServiceNotFoundException);
+  });
+
+  it('should raise an error if the noi already has the tag', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(mockNoiEntityWithTags);
+    tagRepositoryMock.findOne.mockResolvedValue(mockTagEntity);
+
+    await expect(service.addTagToNoticeOfIntent('noi-1', 'tag-name')).rejects.toThrow(ServiceValidationException);
+  });
+
+  it('should throw an error if the noi does not have any tags when deleting', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(mockNoiEntityWithoutTags);
+    tagRepositoryMock.findOne.mockResolvedValue(mockTagEntity);
+
+    await expect(service.removeTagFromNoticeOfIntent('noi-1', 'tag-name')).rejects.toThrow(ServiceValidationException);
+  });
+
+  it('should throw an error if the noi does not have the tag requested when deleting', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(mockNoiEntityWithDifferentTags);
+    tagRepositoryMock.findOne.mockResolvedValue(mockTagEntity);
+
+    await expect(service.removeTagFromNoticeOfIntent('noi-1', 'tag-name')).rejects.toThrow(ServiceValidationException);
+  });
+
+  it('should delete the tag from noi if exists', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(mockNoiEntityWithTags);
+    tagRepositoryMock.findOne.mockResolvedValue(mockTagEntity);
+    noiRepositoryMock.save.mockResolvedValue(mockNoiEntityWithoutTags);
+
+    await service.removeTagFromNoticeOfIntent('noi-1', 'tag-name');
+    expect(mockNoiEntityWithTags.tags.length).toEqual(0);
+    expect(noiRepositoryMock.save).toHaveBeenCalledTimes(1);
+  });
+
+  it('should return noi tags', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(mockNoiEntityWithTags);
+    tagRepositoryMock.findOne.mockResolvedValue(mockTagEntity);
+
+    const result = await service.getNoticeOfIntentTags('noi-1');
+    expect(result).toBeTruthy();
+    expect(result.length).toEqual(1);
+  });
+
+  it('should return empty array if noi does not have tags', async () => {
+    noiRepositoryMock.findOne.mockResolvedValue(mockNoiEntityWithoutTags);
+
+    const result = await service.getNoticeOfIntentTags('noi-1');
+    expect(result).toEqual([]);
+    expect(result.length).toEqual(0);
+  });
 });
diff --git a/services/apps/alcs/test/mocks/mockEntities.ts b/services/apps/alcs/test/mocks/mockEntities.ts
index 33077d062..6906650d9 100644
--- a/services/apps/alcs/test/mocks/mockEntities.ts
+++ b/services/apps/alcs/test/mocks/mockEntities.ts
@@ -24,6 +24,8 @@ import { AssigneeDto, UserDto } from '../../src/user/user.dto';
 import { User } from '../../src/user/user.entity';
 import { TagCategory } from '../../src/alcs/tag/tag-category/tag-category.entity';
 import { Tag } from '../../src/alcs/tag/tag.entity';
+import { NoticeOfIntent } from '../../src/alcs/notice-of-intent/notice-of-intent.entity';
+import { NoticeOfIntentType } from '../../src/alcs/notice-of-intent/notice-of-intent-type/notice-of-intent-type.entity';
 
 const initCardStatusMockEntity = (): CardStatus => {
   const cardStatus = new CardStatus();
@@ -115,6 +117,19 @@ const initApplicationTypeMockEntity = (): ApplicationType => {
   return applicationType;
 };
 
+const initNoticeOfIntentTypeMockEntity = (): NoticeOfIntentType => {
+  const noticeOfIntentType = new NoticeOfIntentType();
+  noticeOfIntentType.code = 'type_1';
+  noticeOfIntentType.description = 'noi desc 1';
+  noticeOfIntentType.label = 'noi_label';
+  noticeOfIntentType.shortLabel = 'short_label';
+  noticeOfIntentType.auditDeletedDateAt = new Date(1, 1, 1, 1, 1, 1, 1);
+  noticeOfIntentType.auditCreatedAt = new Date(1, 1, 1, 1, 1, 1, 1);
+  noticeOfIntentType.auditUpdatedAt = new Date(1, 1, 1, 1, 1, 1, 1);
+
+  return noticeOfIntentType;
+};
+
 const initUserMockEntity = (): User => {
   const user = new User();
   user.familyName = 'familyName';
@@ -207,6 +222,28 @@ const initApplicationMockEntity = (fileNumber?: string): Application => {
   return applicationEntity;
 };
 
+const initNoticeOfIntentMockEntity = (fileNumber?: string): NoticeOfIntent => {
+  const noticeOfIntentEntity = new NoticeOfIntent();
+  noticeOfIntentEntity.fileNumber = fileNumber ?? 'app_1';
+  noticeOfIntentEntity.applicant = 'applicant 1';
+  noticeOfIntentEntity.uuid = '1111-1111-1111-1111';
+  noticeOfIntentEntity.auditDeletedDateAt = new Date(1, 1, 1, 1, 1, 1, 1);
+  noticeOfIntentEntity.auditCreatedAt = new Date(1, 1, 1, 1, 1, 1, 1);
+  noticeOfIntentEntity.auditUpdatedAt = new Date(1, 1, 1, 1, 1, 1, 1);
+  noticeOfIntentEntity.card = initCardMockEntity();
+  noticeOfIntentEntity.cardUuid = noticeOfIntentEntity.card.uuid;
+  noticeOfIntentEntity.type = initNoticeOfIntentTypeMockEntity();
+  noticeOfIntentEntity.card.highPriority = false;
+  noticeOfIntentEntity.region = {
+    code: 'fake',
+    label: 'fake',
+    auditCreatedAt: new Date(1, 1, 1, 1, 1, 1, 1),
+    auditUpdatedAt: new Date(1, 1, 1, 1, 1, 1, 1),
+  } as ApplicationRegion;
+
+  return noticeOfIntentEntity;
+};
+
 const initApplicationWithTagsMockEntity = (): Application => {
   const applicationEntity = initApplicationMockEntity();
   const tagEntity = initTagMockEntity();
@@ -215,6 +252,14 @@ const initApplicationWithTagsMockEntity = (): Application => {
   return applicationEntity;
 };
 
+const initNoticeOfIntentWithTagsMockEntity = (): NoticeOfIntent => {
+  const noticeOfIntentEntity = initNoticeOfIntentMockEntity();
+  const tagEntity = initTagMockEntity();
+  noticeOfIntentEntity.tags = [];
+  noticeOfIntentEntity.tags.push(tagEntity);
+  return noticeOfIntentEntity;
+};
+
 const initMockUserDto = (assignee?: User): UserDto => {
   const userEntity = assignee ?? initUserMockEntity();
   const userDto = new UserDto();
@@ -369,4 +414,6 @@ export {
   initTagCategoryMockEntity,
   initTagMockEntity,
   initApplicationWithTagsMockEntity,
+  initNoticeOfIntentMockEntity,
+  initNoticeOfIntentWithTagsMockEntity,
 };