diff --git a/apps/api/src/app/activities/activities.service.ts b/apps/api/src/app/activities/activities.service.ts
index 9fd2a8b61..3cb1b97ed 100644
--- a/apps/api/src/app/activities/activities.service.ts
+++ b/apps/api/src/app/activities/activities.service.ts
@@ -109,6 +109,13 @@ export class ActivitiesService {
     tags,
     userId
   }: { tags: Tag[]; userId: string } & AssetProfileIdentifier) {
+    await this.tagService.validateTagIds(
+      tags.map(({ id }) => {
+        return id;
+      }),
+      userId
+    );
+
     const activities = await this.prismaService.order.findMany({
       where: {
         userId,
diff --git a/apps/api/src/services/tag/tag.service.ts b/apps/api/src/services/tag/tag.service.ts
index 4f2b5c162..f2d7c718b 100644
--- a/apps/api/src/services/tag/tag.service.ts
+++ b/apps/api/src/services/tag/tag.service.ts
@@ -131,6 +131,13 @@ export class TagService {
       return;
     }
 
+    if (!userId) {
+      throw new HttpException(
+        getReasonPhrase(StatusCodes.BAD_REQUEST),
+        StatusCodes.BAD_REQUEST
+      );
+    }
+
     const uniqueTagIds = Array.from(new Set(tagIds));
 
     const tagsCount = await this.prismaService.tag.count({
diff --git a/libs/common/src/lib/dtos/create-order.dto.ts b/libs/common/src/lib/dtos/create-order.dto.ts
index 9236a12d8..36365b7be 100644
--- a/libs/common/src/lib/dtos/create-order.dto.ts
+++ b/libs/common/src/lib/dtos/create-order.dto.ts
@@ -4,6 +4,7 @@ import { IsCurrencyCode } from '@ghostfolio/common/validators/is-currency-code';
 import { AssetClass, AssetSubClass, DataSource, Type } from '@prisma/client';
 import { Transform, TransformFnParams } from 'class-transformer';
 import {
+  ArrayUnique,
   IsArray,
   IsBoolean,
   IsEnum,
@@ -62,8 +63,10 @@ export class CreateOrderDto {
   @IsString()
   symbol: string;
 
+  @ArrayUnique()
   @IsArray()
   @IsOptional()
+  @IsString({ each: true })
   tags?: string[];
 
   @IsEnum(Type)
diff --git a/libs/common/src/lib/dtos/update-order.dto.ts b/libs/common/src/lib/dtos/update-order.dto.ts
index 7843f142c..991479bc8 100644
--- a/libs/common/src/lib/dtos/update-order.dto.ts
+++ b/libs/common/src/lib/dtos/update-order.dto.ts
@@ -4,6 +4,7 @@ import { IsCurrencyCode } from '@ghostfolio/common/validators/is-currency-code';
 import { AssetClass, AssetSubClass, DataSource, Type } from '@prisma/client';
 import { Transform, TransformFnParams } from 'class-transformer';
 import {
+  ArrayUnique,
   IsArray,
   IsEnum,
   IsISO8601,
@@ -63,8 +64,10 @@ export class UpdateOrderDto {
   @IsString()
   symbol: string;
 
+  @ArrayUnique()
   @IsArray()
   @IsOptional()
+  @IsString({ each: true })
   tags?: string[];
 
   @IsString()