diff --git a/src/domain/entities/DomainError.ts b/src/domain/entities/DomainError.ts
new file mode 100644
index 00000000..4d9c6781
--- /dev/null
+++ b/src/domain/entities/DomainError.ts
@@ -0,0 +1,11 @@
+/**
+ * DomainError entity — manually thrown exception provided by business logic
+ */
+export class DomainError extends Error {
+  /**
+   * @param message - description of why the error was thrown
+   */
+  constructor(message: string) {
+    super(message);
+  }
+}
diff --git a/src/domain/service/note.ts b/src/domain/service/note.ts
index 97e6fe07..30f927f2 100644
--- a/src/domain/service/note.ts
+++ b/src/domain/service/note.ts
@@ -1,6 +1,7 @@
 import type { Note, NoteInternalId, NotePublicId } from '@domain/entities/note.js';
 import type NoteRepository from '@repository/note.repository.js';
 import { createPublicId } from '@infrastructure/utils/id.js';
+import { DomainError } from '@domain/entities/DomainError';
 
 /**
  * Note service
@@ -54,7 +55,7 @@ export default class NoteService {
     const updatedNote = await this.repository.updateNoteContentById(id, content);
 
     if (updatedNote === null) {
-      throw new Error(`Note with id ${id} was not updated`);
+      throw new DomainError(`Note with id ${id} was not updated`);
     }
 
     return updatedNote;
@@ -69,7 +70,7 @@ export default class NoteService {
     const note = await this.repository.getNoteById(id);
 
     if (note === null) {
-      throw new Error(`Note with id ${id} was not found`);
+      throw new DomainError(`Note with id ${id} was not found`);
     }
 
     return note;
@@ -84,7 +85,7 @@ export default class NoteService {
     const note = await this.repository.getNoteByPublicId(publicId);
 
     if (note === null) {
-      throw new Error(`Note with public id ${publicId} was not found`);
+      throw new DomainError(`Note with public id ${publicId} was not found`);
     }
 
     return note;
diff --git a/src/domain/service/noteSettings.ts b/src/domain/service/noteSettings.ts
index 18a3c32d..475194d5 100644
--- a/src/domain/service/noteSettings.ts
+++ b/src/domain/service/noteSettings.ts
@@ -7,6 +7,7 @@ import type { Team, TeamMember, TeamMemberCreationAttributes } from '@domain/ent
 import { MemberRole } from '@domain/entities/team.js';
 import type User from '@domain/entities/user.js';
 import { createInvitationHash } from '@infrastructure/utils/invitationHash.js';
+import { DomainError } from '@domain/entities/DomainError';
 
 /**
  * Service responsible for Note Settings
@@ -44,7 +45,7 @@ export default class NoteSettingsService {
      * Check if invitation hash is valid
      */
     if (noteSettings === null) {
-      throw new Error(`Wrong invitation`);
+      throw new DomainError(`Wrong invitation`);
     }
 
     /**
@@ -53,7 +54,7 @@ export default class NoteSettingsService {
     const isUserTeamMember = await this.teamRepository.isUserInTeam(userId, noteSettings.noteId);
 
     if (isUserTeamMember) {
-      throw new Error(`User already in team`);
+      throw new DomainError(`User already in team`);
     }
 
     return await this.teamRepository.createTeamMembership({
@@ -69,7 +70,13 @@ export default class NoteSettingsService {
    * @param id - note internal id
    */
   public async getNoteSettingsByNoteId(id: NoteInternalId): Promise<NoteSettings> {
-    return await this.noteSettingsRepository.getNoteSettingsByNoteId(id);
+    const settings = await this.noteSettingsRepository.getNoteSettingsByNoteId(id);
+
+    if (settings === null) {
+      throw new DomainError(`Note settings not found`);
+    }
+
+    return settings;
   }
 
   /**
@@ -97,6 +104,10 @@ export default class NoteSettingsService {
   public async patchNoteSettingsByNoteId(noteId: NoteInternalId, data: Partial<NoteSettings>): Promise<NoteSettings | null> {
     const noteSettings = await this.noteSettingsRepository.getNoteSettingsByNoteId(noteId);
 
+    if (noteSettings === null) {
+      throw new DomainError(`Note settings not found`);
+    }
+
     return await this.noteSettingsRepository.patchNoteSettingsById(noteSettings.id, data);
   }
 
diff --git a/src/domain/service/user.ts b/src/domain/service/user.ts
index b54a0ea1..3186b445 100644
--- a/src/domain/service/user.ts
+++ b/src/domain/service/user.ts
@@ -3,6 +3,7 @@ import { Provider } from '@repository/user.repository.js';
 import type User from '@domain/entities/user.js';
 import type EditorTool from '@domain/entities/editorTools';
 import type { SharedDomainMethods } from './shared/index.js';
+import { DomainError } from '@domain/entities/DomainError.js';
 
 export {
   Provider
@@ -57,7 +58,7 @@ export default class UserService {
     const user = await this.getUserById(userId);
 
     if (user === null) {
-      throw new Error('User not found');
+      throw new DomainError('User not found');
     }
 
     const userToolsIds = user.editorTools ?? [];
diff --git a/src/presentation/http/decorators/domainError.ts b/src/presentation/http/decorators/domainError.ts
new file mode 100644
index 00000000..05df3ff5
--- /dev/null
+++ b/src/presentation/http/decorators/domainError.ts
@@ -0,0 +1,30 @@
+import { StatusCodes } from 'http-status-codes';
+import type { FastifyReply } from 'fastify';
+
+/**
+ * Custom method for replying with information that business logic dismissed the request for some reason
+ *
+ * Send this error when a domain-level error is thrown
+ *
+ * @example
+ *
+ *  try {
+ *    service.someAction()
+ *  } catch (error: Error) {
+ *    if (error instanceof DomainError) {
+ *      reply.domainError(error.message);
+ *      return;
+ *    }
+ *    throw error;
+ *  }
+ *
+ * @param message - Optional message to send. If not specified, default message will be sent
+ */
+export default async function domainError(this: FastifyReply, message = 'Domain level error'): Promise<void> {
+  await this
+    .code(StatusCodes.BAD_REQUEST)
+    .type('application/json')
+    .send({
+      message,
+    });
+}
\ No newline at end of file
diff --git a/src/presentation/http/decorators/index.ts b/src/presentation/http/decorators/index.ts
index 982f4a9d..3504dfb8 100644
--- a/src/presentation/http/decorators/index.ts
+++ b/src/presentation/http/decorators/index.ts
@@ -2,10 +2,12 @@ import notFound from './notFound.js';
 import forbidden from './forbidden.js';
 import unauthorized from './unauthorized.js';
 import notAcceptable from './notAcceptable.js';
+import domainError from './domainError.js';
 
 export {
   notFound,
   forbidden,
   unauthorized,
-  notAcceptable
+  notAcceptable,
+  domainError
 };
diff --git a/src/presentation/http/fastify.d.ts b/src/presentation/http/fastify.d.ts
index ec723764..b7fc28d5 100644
--- a/src/presentation/http/fastify.d.ts
+++ b/src/presentation/http/fastify.d.ts
@@ -125,5 +125,26 @@ declare module 'fastify' {
      * @param message - Optional message to send. If not specified, default message will be sent
      */
     notAcceptable: (message?: string) => Promise<void>;
+
+    /**
+     * Custom method for replying with information that business logic dismissed the request for some reason
+     *
+     * Send this error when a domain-level error is thrown
+     *
+     * @example
+     *
+     *  try {
+     *    service.someAction()
+     *  } catch (error: Error) {
+     *    if (error instanceof DomainError) {
+     *      reply.domainError(error.message);
+     *      return;
+     *    }
+     *    throw error;
+     *  }
+     *
+     * @param message - Optional message to send. If not specified, default message will be sent
+     */
+    domainError: (message?: string) => Promise<void>;
   }
 }
diff --git a/src/presentation/http/http-api.ts b/src/presentation/http/http-api.ts
index fbb5b20c..63819664 100644
--- a/src/presentation/http/http-api.ts
+++ b/src/presentation/http/http-api.ts
@@ -10,7 +10,7 @@ import fastifySwagger from '@fastify/swagger';
 import fastifySwaggerUI from '@fastify/swagger-ui';
 import addUserIdResolver from '@presentation/http/middlewares/common/userIdResolver.js';
 import cookie from '@fastify/cookie';
-import { notFound, forbidden, unauthorized, notAcceptable } from './decorators/index.js';
+import { notFound, forbidden, unauthorized, notAcceptable, domainError } from './decorators/index.js';
 import NoteRouter from '@presentation/http/router/note.js';
 import OauthRouter from '@presentation/http/router/oauth.js';
 import AuthRouter from '@presentation/http/router/auth.js';
@@ -26,6 +26,7 @@ import NoteListRouter from '@presentation/http/router/noteList.js';
 import { EditorToolSchema } from './schema/EditorTool.js';
 import JoinRouter from '@presentation/http/router/join.js';
 import { JoinSchemaParams, JoinSchemaResponse } from './schema/Join.js';
+import { DomainError } from '@domain/entities/DomainError.js';
 
 
 const appServerLogger = getLogger('appServer');
@@ -81,6 +82,8 @@ export default class HttpApi implements Api {
     this.addPoliciesCheckHook();
 
     await this.addApiRoutes(domainServices);
+
+    this.domainErrorHandler();
   }
 
 
@@ -287,6 +290,7 @@ export default class HttpApi implements Api {
     this.server?.decorateReply('forbidden', forbidden);
     this.server?.decorateReply('unauthorized', unauthorized);
     this.server?.decorateReply('notAcceptable', notAcceptable);
+    this.server?.decorateReply('domainError', domainError);
   }
 
   /**
@@ -329,5 +333,20 @@ export default class HttpApi implements Api {
       });
     });
   }
+
+  /**
+   * Domain error handler
+   */
+  private domainErrorHandler(): void {
+    this.server?.setErrorHandler(function (error, request, reply) {
+      /**
+       * If we have an error that occurs in the domain-level we reply it with special format
+       */
+      if (error instanceof DomainError) {
+        this.log.error(error);
+        void reply.domainError(error.message);
+      }
+    });
+  }
 }
 
diff --git a/src/repository/noteSettings.repository.ts b/src/repository/noteSettings.repository.ts
index 9e35b923..23285665 100644
--- a/src/repository/noteSettings.repository.ts
+++ b/src/repository/noteSettings.repository.ts
@@ -47,7 +47,7 @@ export default class NoteSettingsRepository {
    * @param id - note id
    * @returns found note settings
    */
-  public async getNoteSettingsByNoteId(id: NoteInternalId): Promise<NoteSettings> {
+  public async getNoteSettingsByNoteId(id: NoteInternalId): Promise<NoteSettings | null> {
     return await this.storage.getNoteSettingsByNoteId(id);
   }
 
diff --git a/src/repository/storage/postgres/orm/sequelize/noteSettings.ts b/src/repository/storage/postgres/orm/sequelize/noteSettings.ts
index 49ddd984..89c44b35 100644
--- a/src/repository/storage/postgres/orm/sequelize/noteSettings.ts
+++ b/src/repository/storage/postgres/orm/sequelize/noteSettings.ts
@@ -147,7 +147,7 @@ export default class NoteSettingsSequelizeStorage {
    * @param noteId - note id
    * @returns { Promise<NoteSettings | null> } - note settings
    */
-  public async getNoteSettingsByNoteId(noteId: NoteSettings['noteId']): Promise<NoteSettings> {
+  public async getNoteSettingsByNoteId(noteId: NoteSettings['noteId']): Promise<NoteSettings | null> {
     const settings = await this.model.findOne({
       where: {
         noteId: noteId,
@@ -155,10 +155,7 @@ export default class NoteSettingsSequelizeStorage {
     });
 
     if (!settings) {
-      /**
-       * TODO: improve exceptions
-       */
-      throw new Error('Note settings not found');
+      return null;
     }
 
     return settings;