diff --git a/backend/internal/domain/entities/customer.go b/backend/internal/domain/entities/customer.go
index c6d6daf..39eb16e 100644
--- a/backend/internal/domain/entities/customer.go
+++ b/backend/internal/domain/entities/customer.go
@@ -3,7 +3,7 @@ package entities
 import "github.com/oklog/ulid/v2"
 
 type Customer struct {
-	ID        ulid.ULID
+	EntityBase
 	Name      string
 	CompanyID int
 }
diff --git a/backend/internal/domain/entities/project.go b/backend/internal/domain/entities/project.go
index 310e16a..76f03aa 100644
--- a/backend/internal/domain/entities/project.go
+++ b/backend/internal/domain/entities/project.go
@@ -3,7 +3,7 @@ package entities
 import "github.com/oklog/ulid/v2"
 
 type Project struct {
-	ID         ulid.ULID
+	EntityBase
 	Name       string
 	CustomerID int
 }
diff --git a/frontend/src/types/activity.ts b/frontend/src/types/activity.ts
index acb506a..48a79ed 100644
--- a/frontend/src/types/activity.ts
+++ b/frontend/src/types/activity.ts
@@ -1,11 +1,14 @@
 import { BaseEntity } from "./base";
 import { ActivityDto, ActivityCreateDto, ActivityUpdateDto } from "./dto";
-import { UserId } from "./value-ids";
+import { UserId, ActivityId } from "./value-ids";
 
-export type Activity = Omit<ActivityDto, "createdAt" | "updatedAt" | "lastEditorID"> & BaseEntity;
+export type Activity = Omit<ActivityDto, "id" | "createdAt" | "updatedAt" | "lastEditorID"> & {
+    id: ActivityId;
+} & BaseEntity;
 
 export const mapActivityDtoToActivity = (dto: ActivityDto): Activity => ({
     ...dto,
+    id: dto.id as ActivityId,
     createdAt: new Date(dto.createdAt),
     updatedAt: new Date(dto.updatedAt),
     lastEditorID: dto.lastEditorID as UserId,
diff --git a/frontend/src/types/base.ts b/frontend/src/types/base.ts
index 5c3af01..d51189b 100644
--- a/frontend/src/types/base.ts
+++ b/frontend/src/types/base.ts
@@ -1,6 +1,8 @@
+import { UserId } from "./value-ids";
+
 export type BaseEntity = {
     createdAt: Date;
     updatedAt: Date;
-    lastEditorID: string;
+    lastEditorID: UserId;
 };
 
diff --git a/frontend/src/types/company.ts b/frontend/src/types/company.ts
index 5ef59e5..f64f639 100644
--- a/frontend/src/types/company.ts
+++ b/frontend/src/types/company.ts
@@ -1,11 +1,14 @@
 import { BaseEntity } from "./base";
 import { CompanyDto, CompanyCreateDto, CompanyUpdateDto } from "./dto";
-import { UserId } from "./value-ids";
+import { UserId, CompanyId } from "./value-ids";
 
-export type Company = Omit<CompanyDto, "createdAt" | "updatedAt" | "lastEditorID"> & BaseEntity;
+export type Company = Omit<CompanyDto, "id" | "createdAt" | "updatedAt" | "lastEditorID"> & {
+    id: CompanyId;
+} & BaseEntity;
 
 export const mapCompanyDtoToCompany = (dto: CompanyDto): Company => ({
     ...dto,
+    id: dto.id as CompanyId,
     createdAt: new Date(dto.createdAt),
     updatedAt: new Date(dto.updatedAt),
     lastEditorID: dto.lastEditorID as UserId,
diff --git a/frontend/src/types/customer.ts b/frontend/src/types/customer.ts
index 9a2752a..e9a2810 100644
--- a/frontend/src/types/customer.ts
+++ b/frontend/src/types/customer.ts
@@ -1,11 +1,14 @@
 import { BaseEntity } from "./base";
 import { CustomerDto, CustomerCreateDto, CustomerUpdateDto } from "./dto";
-import { UserId } from "./value-ids";
+import { UserId, CustomerId } from "./value-ids";
 
-export type Customer = Omit<CustomerDto, "createdAt" | "updatedAt" | "lastEditorID"> & BaseEntity;
+export type Customer = Omit<CustomerDto, "id" | "createdAt" | "updatedAt" | "lastEditorID"> & {
+    id: CustomerId;
+} & BaseEntity;
 
 export const mapCustomerDtoToCustomer = (dto: CustomerDto): Customer => ({
     ...dto,
+    id: dto.id as CustomerId,
     createdAt: new Date(dto.createdAt),
     updatedAt: new Date(dto.updatedAt),
     lastEditorID: dto.lastEditorID as UserId,
diff --git a/frontend/src/types/project.ts b/frontend/src/types/project.ts
index 75a6cf7..28ab4b8 100644
--- a/frontend/src/types/project.ts
+++ b/frontend/src/types/project.ts
@@ -1,11 +1,14 @@
 import { BaseEntity } from "./base";
 import { ProjectDto, ProjectCreateDto, ProjectUpdateDto } from "./dto";
-import { UserId } from "./value-ids";
+import { UserId, ProjectId } from "./value-ids";
 
-export type Project = Omit<ProjectDto, "createdAt" | "updatedAt" | "lastEditorID"> & BaseEntity;
+export type Project = Omit<ProjectDto, "id" | "createdAt" | "updatedAt" | "lastEditorID"> & {
+    id: ProjectId;
+} & BaseEntity;
 
 export const mapProjectDtoToProject = (dto: ProjectDto): Project => ({
     ...dto,
+    id: dto.id as ProjectId,
     createdAt: new Date(dto.createdAt),
     updatedAt: new Date(dto.updatedAt),
     lastEditorID: dto.lastEditorID as UserId,
diff --git a/frontend/src/types/timeentry.ts b/frontend/src/types/timeentry.ts
index 4fc674f..6231c26 100644
--- a/frontend/src/types/timeentry.ts
+++ b/frontend/src/types/timeentry.ts
@@ -1,8 +1,9 @@
 import { BaseEntity } from "./base";
 import { TimeEntryDto, TimeEntryCreateDto, TimeEntryUpdateDto } from "./dto";
-import { UserId, ProjectId, ActivityId } from "./value-ids";
+import { UserId, ProjectId, ActivityId, TimeEntryId } from "./value-ids";
 
-export type TimeEntry = Omit<TimeEntryDto, "start" | "end" | "userId" | "projectId" | "activityId" | "lastEditorID" | "createdAt" | "updatedAt"> & {
+export type TimeEntry = Omit<TimeEntryDto, "id" | "start" | "end" | "userId" | "projectId" | "activityId" | "lastEditorID" | "createdAt" | "updatedAt"> & {
+    id: TimeEntryId;
     start: Date;
     end: Date;
     userId: UserId;
@@ -12,6 +13,7 @@ export type TimeEntry = Omit<TimeEntryDto, "start" | "end" | "userId" | "project
 
 export const mapTimeEntryDtoToTimeEntry = (dto: TimeEntryDto): TimeEntry => ({
     ...dto,
+    id: dto.id as TimeEntryId,
     start: new Date(dto.start),
     end: new Date(dto.end),
     userId: dto.userId.toString() as UserId,
diff --git a/frontend/src/types/user.ts b/frontend/src/types/user.ts
index 04cd7a8..63a6c68 100644
--- a/frontend/src/types/user.ts
+++ b/frontend/src/types/user.ts
@@ -2,10 +2,13 @@ import { BaseEntity } from "./base";
 import { UserDto, UserCreateDto, UserUpdateDto } from "./dto";
 import { UserId } from "./value-ids";
 
-export type User = Omit<UserDto, "createdAt" | "updatedAt" | "lastEditorID"> & BaseEntity;
+export type User = Omit<UserDto, "id" | "createdAt" | "updatedAt" | "lastEditorID"> & {
+    id: UserId;
+} & BaseEntity;
 
 export const mapUserDtoToUser = (dto: UserDto): User => ({
     ...dto,
+    id: dto.id as UserId,
     createdAt: new Date(dto.createdAt),
     updatedAt: new Date(dto.updatedAt),
     lastEditorID: dto.lastEditorID as UserId,