diff --git a/CHANGELOG.md b/CHANGELOG.md
index 63922ad72..d1f8b82ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Included cash in the performance calculation of the portfolio
 
+### Fixed
+
+- Fixed the missing validation of the tags when creating or updating an activity
+- Fixed the missing validation of the tags when updating the tags of a holding
+- Fixed an issue where the tags of an activity were lost if updating the activity failed
+- Fixed an issue where the dividends, the interest and the liabilities of asset profiles without market data have been valued at zero in the portfolio calculation
+- Fixed an issue where an error has been reported for asset profiles without market data which do not hold any units
+- Fixed an issue with removing a linked account from a buy, sell or dividend activity
+
 ## 3.27.0 - 2026-07-15
 
 ### Changed
diff --git a/README.md b/README.md
index ce89412a3..473d5c367 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,8 @@ The frontend is built with [Angular](https://angular.dev) and uses [Angular Mate
 
 We provide official container images hosted on [Docker Hub](https://hub.docker.com/r/ghostfolio/ghostfolio) for `linux/amd64`, `linux/arm/v7` and `linux/arm64`.
 
+Find answers to commonly asked questions about self-hosting Ghostfolio in our [Frequently Asked Questions (FAQ)](https://ghostfol.io/en/faq/self-hosting) section.
+
 <div align="center">
 
 [<img src="./apps/client/src/assets/images/button-buy-me-a-coffee.png" width="150" alt="Buy me a coffee button"/>](https://www.buymeacoffee.com/ghostfolio)
diff --git a/apps/api/src/app/account-balance/account-balance.module.ts b/apps/api/src/app/account-balance/account-balance.module.ts
index 02323acc9..f7b1efc51 100644
--- a/apps/api/src/app/account-balance/account-balance.module.ts
+++ b/apps/api/src/app/account-balance/account-balance.module.ts
@@ -1,6 +1,7 @@
 import { AccountService } from '@ghostfolio/api/app/account/account.service';
 import { ExchangeRateDataModule } from '@ghostfolio/api/services/exchange-rate-data/exchange-rate-data.module';
 import { PrismaModule } from '@ghostfolio/api/services/prisma/prisma.module';
+import { TagModule } from '@ghostfolio/api/services/tag/tag.module';
 
 import { Module } from '@nestjs/common';
 
@@ -10,7 +11,7 @@ import { AccountBalanceService } from './account-balance.service';
 @Module({
   controllers: [AccountBalanceController],
   exports: [AccountBalanceService],
-  imports: [ExchangeRateDataModule, PrismaModule],
+  imports: [ExchangeRateDataModule, PrismaModule, TagModule],
   providers: [AccountBalanceService, AccountService]
 })
 export class AccountBalanceModule {}
diff --git a/apps/api/src/app/account/account.module.ts b/apps/api/src/app/account/account.module.ts
index 253c7fb1d..47b859ba3 100644
--- a/apps/api/src/app/account/account.module.ts
+++ b/apps/api/src/app/account/account.module.ts
@@ -7,6 +7,7 @@ import { ConfigurationModule } from '@ghostfolio/api/services/configuration/conf
 import { ExchangeRateDataModule } from '@ghostfolio/api/services/exchange-rate-data/exchange-rate-data.module';
 import { ImpersonationModule } from '@ghostfolio/api/services/impersonation/impersonation.module';
 import { PrismaModule } from '@ghostfolio/api/services/prisma/prisma.module';
+import { TagModule } from '@ghostfolio/api/services/tag/tag.module';
 
 import { Module } from '@nestjs/common';
 
@@ -25,6 +26,7 @@ import { AccountService } from './account.service';
     PortfolioModule,
     PrismaModule,
     RedactValuesInResponseModule,
+    TagModule,
     UserModule
   ],
   providers: [AccountService]
diff --git a/apps/api/src/app/account/account.service.ts b/apps/api/src/app/account/account.service.ts
index d1f4009a9..f84f085a3 100644
--- a/apps/api/src/app/account/account.service.ts
+++ b/apps/api/src/app/account/account.service.ts
@@ -3,10 +3,11 @@ import { PortfolioChangedEvent } from '@ghostfolio/api/events/portfolio-changed.
 import { WHERE_ACCOUNT_NOT_EXCLUDED } from '@ghostfolio/api/helper/account.helper';
 import { ExchangeRateDataService } from '@ghostfolio/api/services/exchange-rate-data/exchange-rate-data.service';
 import { PrismaService } from '@ghostfolio/api/services/prisma/prisma.service';
+import { TagService } from '@ghostfolio/api/services/tag/tag.service';
 import { DATE_FORMAT } from '@ghostfolio/common/helper';
 import { Filter } from '@ghostfolio/common/interfaces';
 
-import { HttpException, Injectable } from '@nestjs/common';
+import { Injectable } from '@nestjs/common';
 import { EventEmitter2 } from '@nestjs/event-emitter';
 import {
   Account,
@@ -19,7 +20,6 @@ import {
 } from '@prisma/client';
 import { Big } from 'big.js';
 import { format } from 'date-fns';
-import { StatusCodes, getReasonPhrase } from 'http-status-codes';
 import { groupBy } from 'lodash';
 
 import { CashDetails } from './interfaces/cash-details.interface';
@@ -30,7 +30,8 @@ export class AccountService {
     private readonly accountBalanceService: AccountBalanceService,
     private readonly eventEmitter: EventEmitter2,
     private readonly exchangeRateDataService: ExchangeRateDataService,
-    private readonly prismaService: PrismaService
+    private readonly prismaService: PrismaService,
+    private readonly tagService: TagService
   ) {}
 
   public async account({
@@ -127,7 +128,7 @@ export class AccountService {
     aUserId: string,
     tagIds?: string[]
   ): Promise<Account> {
-    await this.validateTagIds(tagIds, aUserId);
+    await this.tagService.validateTagIds({ tagIds, userId: aUserId });
 
     const account = await this.prismaService.account.create({
       data: {
@@ -259,15 +260,15 @@ export class AccountService {
 
   public async updateAccount(
     params: {
-      where: Prisma.AccountWhereUniqueInput;
       data: Prisma.AccountUpdateInput;
+      where: Prisma.AccountWhereUniqueInput;
     },
     aUserId: string,
     tagIds?: string[]
   ): Promise<Account> {
     const { data, where } = params;
 
-    await this.validateTagIds(tagIds, aUserId);
+    await this.tagService.validateTagIds({ tagIds, userId: aUserId });
 
     const account = await this.prismaService.account.update({
       data: {
@@ -340,26 +341,4 @@ export class AccountService {
       });
     }
   }
-
-  private async validateTagIds(tagIds: string[], userId: string) {
-    if (!tagIds?.length) {
-      return;
-    }
-
-    const uniqueTagIds = Array.from(new Set(tagIds));
-
-    const tagsCount = await this.prismaService.tag.count({
-      where: {
-        id: { in: uniqueTagIds },
-        OR: [{ userId }, { userId: null }]
-      }
-    });
-
-    if (tagsCount !== uniqueTagIds.length) {
-      throw new HttpException(
-        getReasonPhrase(StatusCodes.BAD_REQUEST),
-        StatusCodes.BAD_REQUEST
-      );
-    }
-  }
 }
diff --git a/apps/api/src/app/activities/activities.controller.ts b/apps/api/src/app/activities/activities.controller.ts
index d00dd7292..21dabc639 100644
--- a/apps/api/src/app/activities/activities.controller.ts
+++ b/apps/api/src/app/activities/activities.controller.ts
@@ -315,11 +315,13 @@ export class ActivitiesController {
       data: {
         ...data,
         date,
-        account: {
-          connect: {
-            id_userId: { id: accountId, userId: this.request.user.id }
-          }
-        },
+        account: accountId
+          ? {
+              connect: {
+                id_userId: { id: accountId, userId: this.request.user.id }
+              }
+            }
+          : { disconnect: true },
         SymbolProfile: {
           connect: {
             dataSource_symbol: {
@@ -338,6 +340,7 @@ export class ActivitiesController {
         }),
         user: { connect: { id: this.request.user.id } }
       },
+      userId: this.request.user.id,
       where: {
         id
       }
diff --git a/apps/api/src/app/activities/activities.module.ts b/apps/api/src/app/activities/activities.module.ts
index 661163ff1..34091ba5e 100644
--- a/apps/api/src/app/activities/activities.module.ts
+++ b/apps/api/src/app/activities/activities.module.ts
@@ -14,6 +14,7 @@ import { MarketDataModule } from '@ghostfolio/api/services/market-data/market-da
 import { PrismaModule } from '@ghostfolio/api/services/prisma/prisma.module';
 import { DataGatheringQueueModule } from '@ghostfolio/api/services/queues/data-gathering/data-gathering.module';
 import { SymbolProfileModule } from '@ghostfolio/api/services/symbol-profile/symbol-profile.module';
+import { TagModule } from '@ghostfolio/api/services/tag/tag.module';
 
 import { Module } from '@nestjs/common';
 
@@ -36,6 +37,7 @@ import { ActivitiesService } from './activities.service';
     RedactValuesInResponseModule,
     RedisCacheModule,
     SymbolProfileModule,
+    TagModule,
     TransformDataSourceInRequestModule,
     TransformDataSourceInResponseModule
   ],
diff --git a/apps/api/src/app/activities/activities.service.ts b/apps/api/src/app/activities/activities.service.ts
index 427cddf4c..df616a5dd 100644
--- a/apps/api/src/app/activities/activities.service.ts
+++ b/apps/api/src/app/activities/activities.service.ts
@@ -12,6 +12,7 @@ import { MarketDataService } from '@ghostfolio/api/services/market-data/market-d
 import { PrismaService } from '@ghostfolio/api/services/prisma/prisma.service';
 import { DataGatheringService } from '@ghostfolio/api/services/queues/data-gathering/data-gathering.service';
 import { SymbolProfileService } from '@ghostfolio/api/services/symbol-profile/symbol-profile.service';
+import { TagService } from '@ghostfolio/api/services/tag/tag.service';
 import {
   DATA_GATHERING_QUEUE_PRIORITY_HIGH,
   GATHER_ASSET_PROFILE_PROCESS_JOB_NAME,
@@ -61,7 +62,8 @@ export class ActivitiesService {
     private readonly exchangeRateDataService: ExchangeRateDataService,
     private readonly marketDataService: MarketDataService,
     private readonly prismaService: PrismaService,
-    private readonly symbolProfileService: SymbolProfileService
+    private readonly symbolProfileService: SymbolProfileService,
+    private readonly tagService: TagService
   ) {}
 
   public areCashActivitiesExcludedByFilters(filters: Filter[] = []) {
@@ -107,6 +109,13 @@ export class ActivitiesService {
     tags,
     userId
   }: { tags: Tag[]; userId: string } & AssetProfileIdentifier) {
+    await this.tagService.validateTagIds({
+      userId,
+      tagIds: tags.map(({ id }) => {
+        return id;
+      })
+    });
+
     const activities = await this.prismaService.order.findMany({
       where: {
         userId,
@@ -153,6 +162,15 @@ export class ActivitiesService {
       userId: string;
     }
   ): Promise<Order> {
+    const tags = data.tags ?? [];
+
+    await this.tagService.validateTagIds({
+      tagIds: tags.map(({ id }) => {
+        return id;
+      }),
+      userId: data.userId
+    });
+
     let account: Prisma.AccountCreateNestedOneWithoutActivitiesInput;
 
     if (data.accountId) {
@@ -167,7 +185,6 @@ export class ActivitiesService {
     }
 
     const accountId = data.accountId;
-    const tags = data.tags ?? [];
     const updateAccountBalance = data.updateAccountBalance ?? false;
     const userId = data.userId;
 
@@ -932,6 +949,7 @@ export class ActivitiesService {
 
   public async updateActivity({
     data,
+    userId,
     where
   }: {
     data: Prisma.OrderUpdateInput & {
@@ -942,14 +960,22 @@ export class ActivitiesService {
       tags?: { id: string }[];
       type?: ActivityType;
     };
+    userId: string;
     where: Prisma.OrderWhereUniqueInput;
   }): Promise<Order> {
+    const tags = data.tags ?? [];
+
+    await this.tagService.validateTagIds({
+      userId,
+      tagIds: tags.map(({ id }) => {
+        return id;
+      })
+    });
+
     if (!data.comment) {
       data.comment = null;
     }
 
-    const tags = data.tags ?? [];
-
     let isDraft = false;
 
     if (
@@ -957,10 +983,6 @@ export class ActivitiesService {
       (data.SymbolProfile.connect.dataSource_symbol.dataSource === 'MANUAL' &&
         data.type === 'BUY')
     ) {
-      if (data.account?.connect?.id_userId?.id === null) {
-        data.account = { disconnect: true };
-      }
-
       delete data.SymbolProfile.connect;
       delete data.SymbolProfile.update.name;
     } else {
@@ -989,19 +1011,13 @@ export class ActivitiesService {
     delete data.symbol;
     delete data.tags;
 
-    // Remove existing tags
-    await this.prismaService.order.update({
-      where,
-      data: { tags: { set: [] } }
-    });
-
     const activity = await this.prismaService.order.update({
       where,
       data: {
         ...data,
         isDraft,
         tags: {
-          connect: tags
+          set: tags
         }
       }
     });
diff --git a/apps/api/src/app/endpoints/ai/ai.module.ts b/apps/api/src/app/endpoints/ai/ai.module.ts
index 5267f40c8..d5cf0e3e9 100644
--- a/apps/api/src/app/endpoints/ai/ai.module.ts
+++ b/apps/api/src/app/endpoints/ai/ai.module.ts
@@ -20,6 +20,7 @@ import { PrismaModule } from '@ghostfolio/api/services/prisma/prisma.module';
 import { PropertyModule } from '@ghostfolio/api/services/property/property.module';
 import { PortfolioSnapshotQueueModule } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.module';
 import { SymbolProfileModule } from '@ghostfolio/api/services/symbol-profile/symbol-profile.module';
+import { TagModule } from '@ghostfolio/api/services/tag/tag.module';
 
 import { Module } from '@nestjs/common';
 
@@ -44,6 +45,7 @@ import { AiService } from './ai.service';
     PropertyModule,
     RedisCacheModule,
     SymbolProfileModule,
+    TagModule,
     UserModule
   ],
   providers: [
diff --git a/apps/api/src/app/endpoints/benchmarks/benchmarks.module.ts b/apps/api/src/app/endpoints/benchmarks/benchmarks.module.ts
index 2bcd6177d..3c540c337 100644
--- a/apps/api/src/app/endpoints/benchmarks/benchmarks.module.ts
+++ b/apps/api/src/app/endpoints/benchmarks/benchmarks.module.ts
@@ -23,6 +23,7 @@ import { PrismaModule } from '@ghostfolio/api/services/prisma/prisma.module';
 import { PropertyModule } from '@ghostfolio/api/services/property/property.module';
 import { PortfolioSnapshotQueueModule } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.module';
 import { SymbolProfileModule } from '@ghostfolio/api/services/symbol-profile/symbol-profile.module';
+import { TagModule } from '@ghostfolio/api/services/tag/tag.module';
 
 import { Module } from '@nestjs/common';
 
@@ -46,6 +47,7 @@ import { BenchmarksService } from './benchmarks.service';
     RedisCacheModule,
     SymbolModule,
     SymbolProfileModule,
+    TagModule,
     TransformDataSourceInRequestModule,
     TransformDataSourceInResponseModule,
     UserModule
diff --git a/apps/api/src/app/endpoints/public/public.module.ts b/apps/api/src/app/endpoints/public/public.module.ts
index e8395228f..b992694c5 100644
--- a/apps/api/src/app/endpoints/public/public.module.ts
+++ b/apps/api/src/app/endpoints/public/public.module.ts
@@ -18,6 +18,7 @@ import { MarketDataModule } from '@ghostfolio/api/services/market-data/market-da
 import { PrismaModule } from '@ghostfolio/api/services/prisma/prisma.module';
 import { PortfolioSnapshotQueueModule } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.module';
 import { SymbolProfileModule } from '@ghostfolio/api/services/symbol-profile/symbol-profile.module';
+import { TagModule } from '@ghostfolio/api/services/tag/tag.module';
 
 import { Module } from '@nestjs/common';
 
@@ -38,6 +39,7 @@ import { PublicController } from './public.controller';
     PrismaModule,
     RedisCacheModule,
     SymbolProfileModule,
+    TagModule,
     TransformDataSourceInRequestModule,
     UserModule
   ],
diff --git a/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-cash.spec.ts b/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-cash.spec.ts
index 5ae61590b..2dcd7565e 100644
--- a/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-cash.spec.ts
+++ b/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-cash.spec.ts
@@ -91,6 +91,7 @@ describe('PortfolioCalculator', () => {
       accountBalanceService,
       null,
       exchangeRateDataService,
+      null,
       null
     );
 
@@ -122,6 +123,7 @@ describe('PortfolioCalculator', () => {
       exchangeRateDataService,
       null,
       null,
+      null,
       null
     );
 
diff --git a/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-fee.spec.ts b/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-fee.spec.ts
index e5798818f..4e413c0c5 100644
--- a/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-fee.spec.ts
+++ b/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-fee.spec.ts
@@ -113,7 +113,7 @@ describe('PortfolioCalculator', () => {
       expect(portfolioSnapshot).toMatchObject({
         currentValueInBaseCurrency: new Big('0'),
         errors: [],
-        hasErrors: true,
+        hasErrors: false,
         positions: [],
         totalFeesWithCurrencyEffect: new Big('49'),
         totalInterestWithCurrencyEffect: new Big('0'),
diff --git a/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator.ts b/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator.ts
index 4348ca3a4..18a8f7cd8 100644
--- a/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator.ts
+++ b/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator.ts
@@ -233,6 +233,36 @@ export class RoaiPortfolioCalculator extends PortfolioCalculator {
       };
     }
 
+    // The dividends, the interest and the liabilities are derived from the
+    // activities only. Accumulate them upfront so that they survive the bail
+    // out for symbols without a market price below.
+    for (const order of orders) {
+      const exchangeRateAtOrderDate = exchangeRates[order.date];
+
+      if (order.type === 'DIVIDEND') {
+        const dividend = order.quantity.mul(order.unitPrice);
+
+        totalDividend = totalDividend.plus(dividend);
+        totalDividendInBaseCurrency = totalDividendInBaseCurrency.plus(
+          dividend.mul(exchangeRateAtOrderDate ?? 1)
+        );
+      } else if (order.type === 'INTEREST') {
+        const interest = order.quantity.mul(order.unitPrice);
+
+        totalInterest = totalInterest.plus(interest);
+        totalInterestInBaseCurrency = totalInterestInBaseCurrency.plus(
+          interest.mul(exchangeRateAtOrderDate ?? 1)
+        );
+      } else if (order.type === 'LIABILITY') {
+        const liabilities = order.quantity.mul(order.unitPrice);
+
+        totalLiabilities = totalLiabilities.plus(liabilities);
+        totalLiabilitiesInBaseCurrency = totalLiabilitiesInBaseCurrency.plus(
+          liabilities.mul(exchangeRateAtOrderDate ?? 1)
+        );
+      }
+    }
+
     const dateOfFirstTransaction = new Date(orders[0].date);
 
     const endDateString = format(end, DATE_FORMAT);
@@ -260,7 +290,20 @@ export class RoaiPortfolioCalculator extends PortfolioCalculator {
       !unitPriceAtEndDate ||
       (!unitPriceAtStartDate && isBefore(dateOfFirstTransaction, start))
     ) {
+      // A missing market price can only affect the units which are held. The
+      // dividends, the interest and the liabilities do not hold any units and
+      // are therefore not in error.
+      const hasActivitiesWithUnits = orders.some(({ type }) => {
+        return ['BUY', 'SELL'].includes(type);
+      });
+
       return {
+        totalDividend,
+        totalDividendInBaseCurrency,
+        totalInterest,
+        totalInterestInBaseCurrency,
+        totalLiabilities,
+        totalLiabilitiesInBaseCurrency,
         currentValues: {},
         currentValuesWithCurrencyEffect: {},
         feesWithCurrencyEffect: new Big(0),
@@ -268,7 +311,7 @@ export class RoaiPortfolioCalculator extends PortfolioCalculator {
         grossPerformancePercentage: new Big(0),
         grossPerformancePercentageWithCurrencyEffect: new Big(0),
         grossPerformanceWithCurrencyEffect: new Big(0),
-        hasErrors: true,
+        hasErrors: hasActivitiesWithUnits,
         initialValue: new Big(0),
         initialValueWithCurrencyEffect: new Big(0),
         investmentValuesAccumulated: {},
@@ -285,14 +328,8 @@ export class RoaiPortfolioCalculator extends PortfolioCalculator {
         timeWeightedInvestmentValuesWithCurrencyEffect: {},
         timeWeightedInvestmentWithCurrencyEffect: new Big(0),
         totalAccountBalanceInBaseCurrency: new Big(0),
-        totalDividend: new Big(0),
-        totalDividendInBaseCurrency: new Big(0),
-        totalInterest: new Big(0),
-        totalInterestInBaseCurrency: new Big(0),
         totalInvestment: new Big(0),
-        totalInvestmentWithCurrencyEffect: new Big(0),
-        totalLiabilities: new Big(0),
-        totalLiabilitiesInBaseCurrency: new Big(0)
+        totalInvestmentWithCurrencyEffect: new Big(0)
       };
     }
 
@@ -412,29 +449,6 @@ export class RoaiPortfolioCalculator extends PortfolioCalculator {
 
       const exchangeRateAtOrderDate = exchangeRates[order.date];
 
-      if (order.type === 'DIVIDEND') {
-        const dividend = order.quantity.mul(order.unitPrice);
-
-        totalDividend = totalDividend.plus(dividend);
-        totalDividendInBaseCurrency = totalDividendInBaseCurrency.plus(
-          dividend.mul(exchangeRateAtOrderDate ?? 1)
-        );
-      } else if (order.type === 'INTEREST') {
-        const interest = order.quantity.mul(order.unitPrice);
-
-        totalInterest = totalInterest.plus(interest);
-        totalInterestInBaseCurrency = totalInterestInBaseCurrency.plus(
-          interest.mul(exchangeRateAtOrderDate ?? 1)
-        );
-      } else if (order.type === 'LIABILITY') {
-        const liabilities = order.quantity.mul(order.unitPrice);
-
-        totalLiabilities = totalLiabilities.plus(liabilities);
-        totalLiabilitiesInBaseCurrency = totalLiabilitiesInBaseCurrency.plus(
-          liabilities.mul(exchangeRateAtOrderDate ?? 1)
-        );
-      }
-
       if (order.itemType === 'start') {
         // Take the unit price of the order as the market price if there are no
         // orders of this symbol before the start date
diff --git a/apps/api/src/app/portfolio/portfolio.module.ts b/apps/api/src/app/portfolio/portfolio.module.ts
index d818195ca..7f7a894df 100644
--- a/apps/api/src/app/portfolio/portfolio.module.ts
+++ b/apps/api/src/app/portfolio/portfolio.module.ts
@@ -20,6 +20,7 @@ import { PrismaModule } from '@ghostfolio/api/services/prisma/prisma.module';
 import { DataGatheringQueueModule } from '@ghostfolio/api/services/queues/data-gathering/data-gathering.module';
 import { PortfolioSnapshotQueueModule } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.module';
 import { SymbolProfileModule } from '@ghostfolio/api/services/symbol-profile/symbol-profile.module';
+import { TagModule } from '@ghostfolio/api/services/tag/tag.module';
 
 import { Module } from '@nestjs/common';
 
@@ -50,6 +51,7 @@ import { RulesService } from './rules.service';
     RedactValuesInResponseModule,
     RedisCacheModule,
     SymbolProfileModule,
+    TagModule,
     TransformDataSourceInRequestModule,
     TransformDataSourceInResponseModule,
     UserModule
diff --git a/apps/api/src/app/portfolio/portfolio.service.spec.ts b/apps/api/src/app/portfolio/portfolio.service.spec.ts
index adddb4013..c16590cce 100644
--- a/apps/api/src/app/portfolio/portfolio.service.spec.ts
+++ b/apps/api/src/app/portfolio/portfolio.service.spec.ts
@@ -54,6 +54,7 @@ describe('PortfolioService', () => {
       null,
       null,
       exchangeRateDataService,
+      null,
       null
     );
 
@@ -67,6 +68,7 @@ describe('PortfolioService', () => {
       exchangeRateDataService,
       null,
       null,
+      null,
       null
     );
 
diff --git a/apps/api/src/services/tag/tag.service.ts b/apps/api/src/services/tag/tag.service.ts
index d967ce854..38fb90a69 100644
--- a/apps/api/src/services/tag/tag.service.ts
+++ b/apps/api/src/services/tag/tag.service.ts
@@ -1,7 +1,8 @@
 import { PrismaService } from '@ghostfolio/api/services/prisma/prisma.service';
 
-import { Injectable } from '@nestjs/common';
+import { HttpException, Injectable } from '@nestjs/common';
 import { Prisma, Tag } from '@prisma/client';
+import { StatusCodes, getReasonPhrase } from 'http-status-codes';
 
 @Injectable()
 export class TagService {
@@ -124,4 +125,39 @@ export class TagService {
       where
     });
   }
+
+  public async validateTagIds({
+    tagIds,
+    userId
+  }: {
+    tagIds: string[];
+    userId: string;
+  }) {
+    if (!tagIds?.length) {
+      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({
+      where: {
+        id: { in: uniqueTagIds },
+        OR: [{ userId }, { userId: null }]
+      }
+    });
+
+    if (tagsCount !== uniqueTagIds.length) {
+      throw new HttpException(
+        getReasonPhrase(StatusCodes.BAD_REQUEST),
+        StatusCodes.BAD_REQUEST
+      );
+    }
+  }
 }
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()