diff --git a/packages/backend/src/core/ClipService.ts b/packages/backend/src/core/ClipService.ts
index bb8be26ce6c5..b69ca8362019 100644
--- a/packages/backend/src/core/ClipService.ts
+++ b/packages/backend/src/core/ClipService.ts
@@ -20,6 +20,8 @@ export class ClipService {
 	public static AlreadyAddedError = class extends Error {};
 	public static TooManyClipNotesError = class extends Error {};
 	public static TooManyClipsError = class extends Error {};
+	public static ClipLimitExceededError = class extends Error {};
+	public static ClipNotesLimitExceededError = class extends Error {};
 
 	constructor(
 		@Inject(DI.clipsRepository)
@@ -38,13 +40,26 @@ export class ClipService {
 
 	@bindThis
 	public async create(me: MiLocalUser, name: string, isPublic: boolean, description: string | null): Promise<MiClip> {
+		const policies = await this.roleService.getUserPolicies(me.id);
+
 		const currentCount = await this.clipsRepository.countBy({
 			userId: me.id,
 		});
-		if (currentCount > (await this.roleService.getUserPolicies(me.id)).clipLimit) {
+		if (currentCount >= policies.clipLimit) {
 			throw new ClipService.TooManyClipsError();
 		}
 
+		const currentNoteCounts = await this.clipNotesRepository
+			.createQueryBuilder('cn')
+			.select('COUNT(*)')
+			.innerJoin('cn.clip', 'c')
+			.where('c.userId = :userId', { userId: me.id })
+			.groupBy('cn.clipId')
+			.getRawMany<{ count: number }>();
+		if (currentNoteCounts.some((x) => x.count > policies.noteEachClipsLimit)) {
+			throw new ClipService.ClipNotesLimitExceededError();
+		}
+
 		const clip = await this.clipsRepository.insert({
 			id: this.idService.gen(),
 			userId: me.id,
@@ -67,6 +82,26 @@ export class ClipService {
 			throw new ClipService.NoSuchClipError();
 		}
 
+		const policies = await this.roleService.getUserPolicies(me.id);
+
+		const currentCount = await this.clipsRepository.countBy({
+			userId: me.id,
+		});
+		if (currentCount > policies.clipLimit) {
+			throw new ClipService.ClipLimitExceededError();
+		}
+
+		const currentNoteCounts = await this.clipNotesRepository
+			.createQueryBuilder('cn')
+			.select('COUNT(*)')
+			.innerJoin('cn.clip', 'c')
+			.where('c.userId = :userId', { userId: me.id })
+			.groupBy('cn.clipId')
+			.getRawMany<{ count: number }>();
+		if (currentNoteCounts.some((x) => x.count > policies.noteEachClipsLimit)) {
+			throw new ClipService.ClipNotesLimitExceededError();
+		}
+
 		await this.clipsRepository.update(clip.id, {
 			name: name,
 			description: description,
@@ -99,10 +134,30 @@ export class ClipService {
 			throw new ClipService.NoSuchClipError();
 		}
 
-		const currentCount = await this.clipNotesRepository.countBy({
+		const policies = await this.roleService.getUserPolicies(me.id);
+
+		const currentClipCount = await this.clipsRepository.countBy({
+			userId: me.id,
+		});
+		if (currentClipCount > policies.clipLimit) {
+			throw new ClipService.ClipLimitExceededError();
+		}
+
+		const currentNoteCounts = await this.clipNotesRepository
+			.createQueryBuilder('cn')
+			.select('COUNT(*)')
+			.innerJoin('cn.clip', 'c')
+			.where('c.userId = :userId', { userId: me.id })
+			.groupBy('cn.clipId')
+			.getRawMany<{ count: number }>();
+		if (currentNoteCounts.some((x) => x.count > policies.noteEachClipsLimit)) {
+			throw new ClipService.ClipNotesLimitExceededError();
+		}
+
+		const currentNoteCount = await this.clipNotesRepository.countBy({
 			clipId: clip.id,
 		});
-		if (currentCount > (await this.roleService.getUserPolicies(me.id)).noteEachClipsLimit) {
+		if (currentNoteCount >= policies.noteEachClipsLimit) {
 			throw new ClipService.TooManyClipNotesError();
 		}
 
diff --git a/packages/backend/src/core/UserListService.ts b/packages/backend/src/core/UserListService.ts
index c16af88ceff4..09a25079db7b 100644
--- a/packages/backend/src/core/UserListService.ts
+++ b/packages/backend/src/core/UserListService.ts
@@ -95,7 +95,7 @@ export class UserListService implements OnApplicationShutdown, OnModuleInit {
 		const currentCount = await this.userListMembershipsRepository.countBy({
 			userListId: list.id,
 		});
-		if (currentCount > (await this.roleService.getUserPolicies(me.id)).userEachUserListsLimit) {
+		if (currentCount >= (await this.roleService.getUserPolicies(me.id)).userEachUserListsLimit) {
 			throw new UserListService.TooManyUsersError();
 		}
 
diff --git a/packages/backend/src/server/api/endpoints/antennas/create.ts b/packages/backend/src/server/api/endpoints/antennas/create.ts
index 1181998a33dc..8412e1a28f26 100644
--- a/packages/backend/src/server/api/endpoints/antennas/create.ts
+++ b/packages/backend/src/server/api/endpoints/antennas/create.ts
@@ -95,7 +95,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			const currentAntennasCount = await this.antennasRepository.countBy({
 				userId: me.id,
 			});
-			if (currentAntennasCount > (await this.roleService.getUserPolicies(me.id)).antennaLimit) {
+			if (currentAntennasCount >= (await this.roleService.getUserPolicies(me.id)).antennaLimit) {
 				throw new ApiError(meta.errors.tooManyAntennas);
 			}
 
diff --git a/packages/backend/src/server/api/endpoints/antennas/update.ts b/packages/backend/src/server/api/endpoints/antennas/update.ts
index d962db317e30..aa1e7f3372ae 100644
--- a/packages/backend/src/server/api/endpoints/antennas/update.ts
+++ b/packages/backend/src/server/api/endpoints/antennas/update.ts
@@ -9,6 +9,7 @@ import type { AntennasRepository, UserListsRepository } from '@/models/_.js';
 import { GlobalEventService } from '@/core/GlobalEventService.js';
 import { AntennaEntityService } from '@/core/entities/AntennaEntityService.js';
 import { DI } from '@/di-symbols.js';
+import { RoleService } from '@/core/RoleService.js';
 import { ApiError } from '../../error.js';
 
 export const meta = {
@@ -33,6 +34,12 @@ export const meta = {
 			code: 'NO_SUCH_USER_LIST',
 			id: '1c6b35c9-943e-48c2-81e4-2844989407f7',
 		},
+
+		antennaLimitExceeded: {
+			message: 'You cannot update the antenna because you have exceeded the limit of antennas.',
+			code: 'ANTENNA_LIMIT_EXCEEDED',
+			id: '3166a92e-09d9-4c09-afa3-1dbe34a3afcf',
+		},
 	},
 
 	res: {
@@ -83,6 +90,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 
 		private antennaEntityService: AntennaEntityService,
 		private globalEventService: GlobalEventService,
+		private roleService: RoleService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
 			if (ps.keywords && ps.excludeKeywords) {
@@ -100,6 +108,13 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				throw new ApiError(meta.errors.noSuchAntenna);
 			}
 
+			const currentAntennasCount = await this.antennasRepository.countBy({
+				userId: me.id,
+			});
+			if (currentAntennasCount > (await this.roleService.getUserPolicies(me.id)).antennaLimit) {
+				throw new ApiError(meta.errors.antennaLimitExceeded);
+			}
+
 			let userList;
 
 			if ((ps.src === 'list' || antenna.src === 'list') && ps.userListId) {
diff --git a/packages/backend/src/server/api/endpoints/clips/add-note.ts b/packages/backend/src/server/api/endpoints/clips/add-note.ts
index 7f055f6e3f30..12718e2d43f5 100644
--- a/packages/backend/src/server/api/endpoints/clips/add-note.ts
+++ b/packages/backend/src/server/api/endpoints/clips/add-note.ts
@@ -48,6 +48,18 @@ export const meta = {
 			code: 'TOO_MANY_CLIP_NOTES',
 			id: 'f0dba960-ff73-4615-8df4-d6ac5d9dc118',
 		},
+
+		clipLimitExceeded: {
+			message: 'You cannot add a note to the clip because you have exceeded the limit of clips.',
+			code: 'CLIP_LIMIT_EXCEEDED',
+			id: '456cd06d-9f5b-4793-8108-dffe6e257d98',
+		},
+
+		clipNotesLimitExceeded: {
+			message: 'You cannot add a note to the clip because you have exceeded the limit of notes in other clips.',
+			code: 'CLIP_NOTES_LIMIT_EXCEEDED',
+			id: 'f3d6de24-ad27-418d-9d13-b50165dbce66',
+		},
 	},
 } as const;
 
@@ -77,6 +89,10 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 					throw new ApiError(meta.errors.alreadyClipped);
 				} else if (e instanceof ClipService.TooManyClipNotesError) {
 					throw new ApiError(meta.errors.tooManyClipNotes);
+				} else if (e instanceof ClipService.ClipLimitExceededError) {
+					throw new ApiError(meta.errors.clipLimitExceeded);
+				} else if (e instanceof ClipService.ClipNotesLimitExceededError) {
+					throw new ApiError(meta.errors.clipNotesLimitExceeded);
 				} else {
 					throw e;
 				}
diff --git a/packages/backend/src/server/api/endpoints/clips/create.ts b/packages/backend/src/server/api/endpoints/clips/create.ts
index 3e2d46be4d37..5df457c9110e 100644
--- a/packages/backend/src/server/api/endpoints/clips/create.ts
+++ b/packages/backend/src/server/api/endpoints/clips/create.ts
@@ -32,6 +32,12 @@ export const meta = {
 			code: 'TOO_MANY_CLIPS',
 			id: '920f7c2d-6208-4b76-8082-e632020f5883',
 		},
+
+		clipNotesLimitExceeded: {
+			message: 'You cannot create a clip any more because you have exceeded the limit of notes in a clip.',
+			code: 'CLIP_NOTES_LIMIT_EXCEEDED',
+			id: '1fdd390f-dcd3-4b65-88d9-6476159bc5c8',
+		},
 	},
 } as const;
 
@@ -58,6 +64,8 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			} catch (e) {
 				if (e instanceof ClipService.TooManyClipsError) {
 					throw new ApiError(meta.errors.tooManyClips);
+				} else if (e instanceof ClipService.ClipNotesLimitExceededError) {
+					throw new ApiError(meta.errors.clipNotesLimitExceeded);
 				}
 				throw e;
 			}
diff --git a/packages/backend/src/server/api/endpoints/clips/update.ts b/packages/backend/src/server/api/endpoints/clips/update.ts
index 72d7f3bb5966..dc0c996dc801 100644
--- a/packages/backend/src/server/api/endpoints/clips/update.ts
+++ b/packages/backend/src/server/api/endpoints/clips/update.ts
@@ -25,6 +25,18 @@ export const meta = {
 			code: 'NO_SUCH_CLIP',
 			id: 'b4d92d70-b216-46fa-9a3f-a8c811699257',
 		},
+
+		clipLimitExceeded: {
+			message: 'You cannot update the clip because you have exceeded the limit of clips.',
+			code: 'CLIP_LIMIT_EXCEEDED',
+			id: 'fed46dd9-d99a-4a88-b23f-8d31c80b5b25',
+		},
+
+		clipNotesLimitExceeded: {
+			message: 'You cannot update the clip because you have exceeded the limit of notes in a clip.',
+			code: 'CLIP_NOTES_LIMIT_EXCEEDED',
+			id: '6f02ab37-66a4-4285-afaf-a8b1000e8f3f',
+		},
 	},
 
 	res: {
@@ -58,6 +70,10 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			} catch (e) {
 				if (e instanceof ClipService.NoSuchClipError) {
 					throw new ApiError(meta.errors.noSuchClip);
+				} else if (e instanceof ClipService.ClipLimitExceededError) {
+					throw new ApiError(meta.errors.clipLimitExceeded);
+				} else if (e instanceof ClipService.ClipNotesLimitExceededError) {
+					throw new ApiError(meta.errors.clipNotesLimitExceeded);
 				}
 				throw e;
 			}
diff --git a/packages/backend/src/server/api/endpoints/i/import-antennas.ts b/packages/backend/src/server/api/endpoints/i/import-antennas.ts
index eb9dae0a39cd..a6edeb2225cf 100644
--- a/packages/backend/src/server/api/endpoints/i/import-antennas.ts
+++ b/packages/backend/src/server/api/endpoints/i/import-antennas.ts
@@ -80,7 +80,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 			if (file.size === 0) throw new ApiError(meta.errors.emptyFile);
 			const antennas: (_Antenna & { userListAccts: string[] | null })[] = JSON.parse(await this.downloadService.downloadTextFile(file.url));
 			const currentAntennasCount = await this.antennasRepository.countBy({ userId: me.id });
-			if (currentAntennasCount + antennas.length > (await this.roleService.getUserPolicies(me.id)).antennaLimit) {
+			if (currentAntennasCount + antennas.length >= (await this.roleService.getUserPolicies(me.id)).antennaLimit) {
 				throw new ApiError(meta.errors.tooManyAntennas);
 			}
 			this.queueService.createImportAntennasJob(me, antennas);
diff --git a/packages/backend/src/server/api/endpoints/i/webhooks/create.ts b/packages/backend/src/server/api/endpoints/i/webhooks/create.ts
index 71f9644f6ef3..5a5b9b05543f 100644
--- a/packages/backend/src/server/api/endpoints/i/webhooks/create.ts
+++ b/packages/backend/src/server/api/endpoints/i/webhooks/create.ts
@@ -91,7 +91,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			const currentWebhooksCount = await this.webhooksRepository.countBy({
 				userId: me.id,
 			});
-			if (currentWebhooksCount > (await this.roleService.getUserPolicies(me.id)).webhookLimit) {
+			if (currentWebhooksCount >= (await this.roleService.getUserPolicies(me.id)).webhookLimit) {
 				throw new ApiError(meta.errors.tooManyWebhooks);
 			}
 
diff --git a/packages/backend/src/server/api/endpoints/i/webhooks/update.ts b/packages/backend/src/server/api/endpoints/i/webhooks/update.ts
index 40a2efd4c524..a2e80f76a85d 100644
--- a/packages/backend/src/server/api/endpoints/i/webhooks/update.ts
+++ b/packages/backend/src/server/api/endpoints/i/webhooks/update.ts
@@ -31,6 +31,11 @@ export const meta = {
 			code: 'YOU_ARE_NOT_ADMIN',
 			id: 'a70c7643-1db5-4ebf-becd-ff4b4223cf23',
 		},
+		webhookLimitExceeded: {
+			message: 'You cannot update the webhook because you have exceeded the limit of webhooks.',
+			code: 'WEBHOOK_LIMIT_EXCEEDED',
+			id: 'a261cb2d-867d-47a8-a743-8bbd2c1438b1',
+		},
 	},
 
 } as const;
@@ -62,6 +67,13 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 		private roleService: RoleService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
+			const currentWebhooksCount = await this.webhooksRepository.countBy({
+				userId: me.id,
+			});
+			if (currentWebhooksCount > (await this.roleService.getUserPolicies(me.id)).webhookLimit) {
+				throw new ApiError(meta.errors.webhookLimitExceeded);
+			}
+
 			const webhook = await this.webhooksRepository.findOneBy({
 				id: ps.webhookId,
 				userId: me.id,
diff --git a/packages/backend/src/server/api/endpoints/users/lists/create-from-public.ts b/packages/backend/src/server/api/endpoints/users/lists/create-from-public.ts
index edc1431d6775..394d0fcf78c5 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/create-from-public.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/create-from-public.ts
@@ -61,6 +61,12 @@ export const meta = {
 			code: 'TOO_MANY_USERS',
 			id: '1845ea77-38d1-426e-8e4e-8b83b24f5bd7',
 		},
+
+		listUsersLimitExceeded: {
+			message: 'You cannot create a list because you have exceeded the limit of users in a list.',
+			code: 'LIST_USERS_LIMIT_EXCEEDED',
+			id: '3e205e58-0798-40f2-a589-a78a619ee3d4',
+		},
 	},
 } as const;
 
@@ -99,13 +105,25 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				},
 			});
 			if (!listExist) throw new ApiError(meta.errors.noSuchList);
+
+			const policies = await this.roleService.getUserPolicies(me.id);
 			const currentCount = await this.userListsRepository.countBy({
 				userId: me.id,
 			});
-			if (currentCount > (await this.roleService.getUserPolicies(me.id)).userListLimit) {
+			if (currentCount >= policies.userListLimit) {
 				throw new ApiError(meta.errors.tooManyUserLists);
 			}
 
+			const currentUserCounts = await this.userListMembershipsRepository
+				.createQueryBuilder('ulm')
+				.select('COUNT(*)')
+				.where('ulm.userListUserId = :userId', { userId: me.id })
+				.groupBy('ulm.userListId')
+				.getRawMany<{ count: number }>();
+			if (currentUserCounts.some((x) => x.count > policies.userEachUserListsLimit)) {
+				throw new ApiError(meta.errors.listUsersLimitExceeded);
+			}
+
 			const userList = await this.userListsRepository.insert({
 				id: this.idService.gen(),
 				userId: me.id,
diff --git a/packages/backend/src/server/api/endpoints/users/lists/create.ts b/packages/backend/src/server/api/endpoints/users/lists/create.ts
index bb7017588828..ac6129c5bf58 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/create.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/create.ts
@@ -4,7 +4,7 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import type { UserListsRepository } from '@/models/_.js';
+import type { UserListMembershipsRepository, UserListsRepository } from '@/models/_.js';
 import { IdService } from '@/core/IdService.js';
 import type { MiUserList } from '@/models/UserList.js';
 import { Endpoint } from '@/server/api/endpoint-base.js';
@@ -37,6 +37,12 @@ export const meta = {
 			code: 'TOO_MANY_USERLISTS',
 			id: '0cf21a28-7715-4f39-a20d-777bfdb8d138',
 		},
+
+		listUsersLimitExceeded: {
+			message: 'You cannot create a list because you have exceeded the limit of users in a list.',
+			code: 'LIST_USERS_LIMIT_EXCEEDED',
+			id: 'af66c10d-b0e6-418c-a205-4dd46a482e30',
+		},
 	},
 } as const;
 
@@ -54,18 +60,32 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 		@Inject(DI.userListsRepository)
 		private userListsRepository: UserListsRepository,
 
+		@Inject(DI.userListMembershipsRepository)
+		private userListMembershipsRepository: UserListMembershipsRepository,
+
 		private userListEntityService: UserListEntityService,
 		private idService: IdService,
 		private roleService: RoleService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
+			const policies = await this.roleService.getUserPolicies(me.id);
 			const currentCount = await this.userListsRepository.countBy({
 				userId: me.id,
 			});
-			if (currentCount > (await this.roleService.getUserPolicies(me.id)).userListLimit) {
+			if (currentCount >= policies.userListLimit) {
 				throw new ApiError(meta.errors.tooManyUserLists);
 			}
 
+			const currentUserCounts = await this.userListMembershipsRepository
+				.createQueryBuilder('ulm')
+				.select('COUNT(*)')
+				.where('ulm.userListUserId = :userId', { userId: me.id })
+				.groupBy('ulm.userListId')
+				.getRawMany<{ count: number }>();
+			if (currentUserCounts.some((x) => x.count > policies.userEachUserListsLimit)) {
+				throw new ApiError(meta.errors.listUsersLimitExceeded);
+			}
+
 			const userList = await this.userListsRepository.insert({
 				id: this.idService.gen(),
 				userId: me.id,
diff --git a/packages/backend/src/server/api/endpoints/users/lists/push.ts b/packages/backend/src/server/api/endpoints/users/lists/push.ts
index dd188d5e9a59..4c470787b5f9 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/push.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/push.ts
@@ -10,6 +10,7 @@ import { Endpoint } from '@/server/api/endpoint-base.js';
 import { GetterService } from '@/server/api/GetterService.js';
 import { UserListService } from '@/core/UserListService.js';
 import { DI } from '@/di-symbols.js';
+import { RoleService } from '@/core/RoleService.js';
 import { ApiError } from '../../../error.js';
 
 export const meta = {
@@ -59,6 +60,18 @@ export const meta = {
 			code: 'TOO_MANY_USERS',
 			id: '2dd9752e-a338-413d-8eec-41814430989b',
 		},
+
+		listLimitExceeded: {
+			message: 'You cannot add a user to the list because you have exceeded the limit of lists.',
+			code: 'LIST_LIMIT_EXCEEDED',
+			id: '5906ab2d-c164-44bc-a60a-464beba52be9',
+		},
+
+		listUsersLimitExceeded: {
+			message: 'You cannot add a user to the list because you have exceeded the limit of users in other list.',
+			code: 'LIST_USERS_LIMIT_EXCEEDED',
+			id: 'd1054b77-908a-4f7d-a9cc-44d665267108',
+		},
 	},
 } as const;
 
@@ -85,6 +98,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 
 		private getterService: GetterService,
 		private userListService: UserListService,
+		private roleService: RoleService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
 			// Fetch the list
@@ -97,6 +111,25 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				throw new ApiError(meta.errors.noSuchList);
 			}
 
+			// Check the list limit
+			const policies = await this.roleService.getUserPolicies(me.id);
+			const currentCount = await this.userListsRepository.countBy({
+				userId: me.id,
+			});
+			if (currentCount > policies.userListLimit) {
+				throw new ApiError(meta.errors.listLimitExceeded);
+			}
+
+			const currentUserCounts = await this.userListMembershipsRepository
+				.createQueryBuilder('ulm')
+				.select('COUNT(*)')
+				.where('ulm.userListUserId = :userId', { userId: me.id })
+				.groupBy('ulm.userListId')
+				.getRawMany<{ count: number }>();
+			if (currentUserCounts.some((x) => x.count > policies.userEachUserListsLimit)) {
+				throw new ApiError(meta.errors.listUsersLimitExceeded);
+			}
+
 			// Fetch the user
 			const user = await this.getterService.getUser(ps.userId).catch(err => {
 				if (err.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
diff --git a/packages/backend/src/server/api/endpoints/users/lists/update-membership.ts b/packages/backend/src/server/api/endpoints/users/lists/update-membership.ts
index 3948ae168567..f099be767edf 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/update-membership.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/update-membership.ts
@@ -4,11 +4,12 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import type { UserListsRepository } from '@/models/_.js';
+import type { UserListMembershipsRepository, UserListsRepository } from '@/models/_.js';
 import { Endpoint } from '@/server/api/endpoint-base.js';
 import { GetterService } from '@/server/api/GetterService.js';
 import { DI } from '@/di-symbols.js';
 import { UserListService } from '@/core/UserListService.js';
+import { RoleService } from '@/core/RoleService.js';
 import { ApiError } from '../../../error.js';
 
 export const meta = {
@@ -32,6 +33,18 @@ export const meta = {
 			code: 'NO_SUCH_USER',
 			id: '588e7f72-c744-4a61-b180-d354e912bda2',
 		},
+
+		listLimitExceeded: {
+			message: 'You cannot update the user because you have exceeded the limit of lists.',
+			code: 'LIST_LIMIT_EXCEEDED',
+			id: 'd4005118-e773-4132-bafb-10ba22c78da3',
+		},
+
+		listUsersLimitExceeded: {
+			message: 'You cannot update the user because you have exceeded the limit of users in a list.',
+			code: 'LIST_USERS_LIMIT_EXCEEDED',
+			id: 'db7fe164-73d0-4788-8ed1-b6a19e95990d',
+		},
 	},
 } as const;
 
@@ -51,8 +64,12 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 		@Inject(DI.userListsRepository)
 		private userListsRepository: UserListsRepository,
 
+		@Inject(DI.userListMembershipsRepository)
+		private userListMembershipsRepository: UserListMembershipsRepository,
+
 		private userListService: UserListService,
 		private getterService: GetterService,
+		private roleService: RoleService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
 			// Fetch the list
@@ -65,6 +82,25 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				throw new ApiError(meta.errors.noSuchList);
 			}
 
+			// Check the list limit
+			const policies = await this.roleService.getUserPolicies(me.id);
+			const currentCount = await this.userListsRepository.countBy({
+				userId: me.id,
+			});
+			if (currentCount > policies.userListLimit) {
+				throw new ApiError(meta.errors.listLimitExceeded);
+			}
+
+			const currentUserCounts = await this.userListMembershipsRepository
+				.createQueryBuilder('ulm')
+				.select('COUNT(*)')
+				.where('ulm.userListUserId = :userId', { userId: me.id })
+				.groupBy('ulm.userListId')
+				.getRawMany<{ count: number }>();
+			if (currentUserCounts.some((x) => x.count > policies.userEachUserListsLimit)) {
+				throw new ApiError(meta.errors.listUsersLimitExceeded);
+			}
+
 			// Fetch the user
 			const user = await this.getterService.getUser(ps.userId).catch(err => {
 				if (err.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
diff --git a/packages/backend/src/server/api/endpoints/users/lists/update.ts b/packages/backend/src/server/api/endpoints/users/lists/update.ts
index ae0753f2ceaf..173dfa68b5ea 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/update.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/update.ts
@@ -4,10 +4,11 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import type { UserListsRepository } from '@/models/_.js';
+import type { UserListMembershipsRepository, UserListsRepository } from '@/models/_.js';
 import { Endpoint } from '@/server/api/endpoint-base.js';
 import { UserListEntityService } from '@/core/entities/UserListEntityService.js';
 import { DI } from '@/di-symbols.js';
+import { RoleService } from '@/core/RoleService.js';
 import { ApiError } from '../../../error.js';
 
 export const meta = {
@@ -32,6 +33,18 @@ export const meta = {
 			code: 'NO_SUCH_LIST',
 			id: '796666fe-3dff-4d39-becb-8a5932c1d5b7',
 		},
+
+		listLimitExceeded: {
+			message: 'You cannot update the list because you have exceeded the limit of lists.',
+			code: 'LIST_LIMIT_EXCEEDED',
+			id: '0a1fa63e-3e4c-4bc2-afd1-1ff853b4560e',
+		},
+
+		listUsersLimitExceeded: {
+			message: 'You cannot update the list because you have exceeded the limit of users in a list.',
+			code: 'LIST_USERS_LIMIT_EXCEEDED',
+			id: '831fd3b2-4ac8-421e-89db-bfd98944e529',
+		},
 	},
 } as const;
 
@@ -51,7 +64,11 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 		@Inject(DI.userListsRepository)
 		private userListsRepository: UserListsRepository,
 
+		@Inject(DI.userListMembershipsRepository)
+		private userListMembershipsRepository: UserListMembershipsRepository,
+
 		private userListEntityService: UserListEntityService,
+		private roleService: RoleService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
 			const userList = await this.userListsRepository.findOneBy({
@@ -63,6 +80,24 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				throw new ApiError(meta.errors.noSuchList);
 			}
 
+			const policies = await this.roleService.getUserPolicies(me.id);
+			const currentCount = await this.userListsRepository.countBy({
+				userId: me.id,
+			});
+			if (currentCount > policies.userListLimit) {
+				throw new ApiError(meta.errors.listLimitExceeded);
+			}
+
+			const currentUserCounts = await this.userListMembershipsRepository
+				.createQueryBuilder('ulm')
+				.select('COUNT(*)')
+				.where('ulm.userListUserId = :userId', { userId: me.id })
+				.groupBy('ulm.userListId')
+				.getRawMany<{ count: number }>();
+			if (currentUserCounts.some((x) => x.count > policies.userEachUserListsLimit)) {
+				throw new ApiError(meta.errors.listUsersLimitExceeded);
+			}
+
 			await this.userListsRepository.update(userList.id, {
 				name: ps.name,
 				isPublic: ps.isPublic,
diff --git a/packages/backend/test/e2e/antennas.ts b/packages/backend/test/e2e/antennas.ts
index 215cf652df21..05352916a08a 100644
--- a/packages/backend/test/e2e/antennas.ts
+++ b/packages/backend/test/e2e/antennas.ts
@@ -167,8 +167,7 @@ describe('アンテナ', () => {
 	});
 
 	test('が上限いっぱいまで作成できること', async () => {
-		// antennaLimit + 1まで作れるのがキモ
-		const response = await Promise.all([...Array(DEFAULT_POLICIES.antennaLimit + 1)].map(() => successfulApiCall({
+		const response = await Promise.all([...Array(DEFAULT_POLICIES.antennaLimit)].map(() => successfulApiCall({
 			endpoint: 'antennas/create',
 			parameters: { ...defaultParam },
 			user: alice,
diff --git a/packages/backend/test/e2e/clips.ts b/packages/backend/test/e2e/clips.ts
index 91d8bfa5d6a1..ed5e3dfa9145 100644
--- a/packages/backend/test/e2e/clips.ts
+++ b/packages/backend/test/e2e/clips.ts
@@ -153,8 +153,7 @@ describe('クリップ', () => {
 	});
 
 	test('の作成はポリシーで定められた数以上はできない。', async () => {
-		// ポリシー + 1まで作れるという所がミソ
-		const clipLimit = DEFAULT_POLICIES.clipLimit + 1;
+		const clipLimit = DEFAULT_POLICIES.clipLimit;
 		for (let i = 0; i < clipLimit; i++) {
 			await create();
 		}
@@ -327,10 +326,10 @@ describe('クリップ', () => {
 	});
 
 	test('の一覧(clips/list)が取得できる(上限いっぱい)', async () => {
-		const clipLimit = DEFAULT_POLICIES.clipLimit + 1;
+		const clipLimit = DEFAULT_POLICIES.clipLimit;
 		const clips = await createMany({}, clipLimit);
 		const res = await list({
-			parameters: { limit: 1 }, // FIXME: 無視されて11全部返ってくる
+			parameters: { limit: 1 }, // FIXME: 無視されて10全部返ってくる
 		});
 
 		// 返ってくる配列には順序保障がないのでidでソートして厳密比較
@@ -705,7 +704,7 @@ describe('クリップ', () => {
 
 		// TODO: 17000msくらいかかる...
 		test('をポリシーで定められた上限いっぱい(200)を超えて追加はできない。', async () => {
-			const noteLimit = DEFAULT_POLICIES.noteEachClipsLimit + 1;
+			const noteLimit = DEFAULT_POLICIES.noteEachClipsLimit;
 			const noteList = await Promise.all([...Array(noteLimit)].map((_, i) => post(alice, {
 				text: `test ${i}`,
 			}) as unknown)) as Misskey.entities.Note[];