diff --git a/docs/docs/administration/oauth.md b/docs/docs/administration/oauth.md
index 06fdda699..ae3bf55ce 100644
--- a/docs/docs/administration/oauth.md
+++ b/docs/docs/administration/oauth.md
@@ -81,7 +81,11 @@ Once you have a new OAuth client application configured, Immich can be configure
 
 :::note Claim Options [1]
 
-Claim is only used on user creation and not synchronized after that.
+Claims are applied when a user is first registered. On subsequent logins, claims present in the OAuth profile are synchronized to the Immich user profile. Claims that are absent from the profile are left unchanged.
+
+The storage label is an exception: with the default claim (`preferred_username`), it is only set at registration and is not updated on later logins. To keep the storage label in sync with the IdP, configure a different Storage Label Claim (for example `uid`).
+
+The storage quota claim is a number in GiB: `-1` for unlimited, `0` to block uploads, any positive value for a fixed quota.
 
 :::
 
diff --git a/server/src/services/auth.service.spec.ts b/server/src/services/auth.service.spec.ts
index 0d3771b2e..913620313 100644
--- a/server/src/services/auth.service.spec.ts
+++ b/server/src/services/auth.service.spec.ts
@@ -947,7 +947,7 @@ describe(AuthService.name, () => {
       expect(mocks.user.create).toHaveBeenCalledWith(expect.objectContaining({ quotaSizeInBytes: 1_073_741_824 }));
     });
 
-    it('should ignore a negative quota', async () => {
+    it('should ignore an invalid negative quota', async () => {
       mocks.systemMetadata.get.mockResolvedValue(systemConfigStub.oauthWithStorageQuota);
       mocks.oauth.getProfileAndOAuthSid.mockResolvedValue({
         profile: OAuthProfileFactory.create({ immich_quota: -5 }),
@@ -966,6 +966,25 @@ describe(AuthService.name, () => {
       expect(mocks.user.create).toHaveBeenCalledWith(expect.objectContaining({ quotaSizeInBytes: 1_073_741_824 }));
     });
 
+    it('should set unlimited quota for -1', async () => {
+      mocks.systemMetadata.get.mockResolvedValue(systemConfigStub.oauthWithStorageQuota);
+      mocks.oauth.getProfileAndOAuthSid.mockResolvedValue({
+        profile: OAuthProfileFactory.create({ immich_quota: -1 }),
+      });
+      mocks.user.getAdmin.mockResolvedValue(UserFactory.create({ isAdmin: true }));
+      mocks.user.getByEmail.mockResolvedValue(void 0);
+      mocks.user.create.mockResolvedValue(UserFactory.create({ oauthId: 'oauth-id' }));
+      mocks.session.create.mockResolvedValue(SessionFactory.create());
+
+      await sut.callback(
+        { url: 'http://immich/auth/login?code=abc123', state: 'xyz789', codeVerifier: 'foo' },
+        {},
+        loginDetails,
+      );
+
+      expect(mocks.user.create).toHaveBeenCalledWith(expect.objectContaining({ quotaSizeInBytes: null }));
+    });
+
     it('should set quota for 0 quota', async () => {
       mocks.systemMetadata.get.mockResolvedValue(systemConfigStub.oauthWithStorageQuota);
       mocks.oauth.getProfileAndOAuthSid.mockResolvedValue({ profile: OAuthProfileFactory.create({ immich_quota: 0 }) });
@@ -1185,6 +1204,100 @@ describe(AuthService.name, () => {
       expect(mocks.user.create).toHaveBeenCalledWith(expect.objectContaining({ isAdmin: false }));
     });
 
+    it('should sync the storage quota on subsequent logins when the claim is present', async () => {
+      const user = UserFactory.create({ oauthId: 'oauth-id', quotaSizeInBytes: 1_073_741_824 });
+
+      mocks.systemMetadata.get.mockResolvedValue(systemConfigStub.oauthWithStorageQuota);
+      mocks.oauth.getProfileAndOAuthSid.mockResolvedValue({
+        profile: OAuthProfileFactory.create({ sub: user.oauthId!, immich_quota: 5 }),
+      });
+      mocks.user.getByOAuthId.mockResolvedValue(user);
+      mocks.user.update.mockResolvedValue({ ...user, quotaSizeInBytes: 5_368_709_120 });
+      mocks.session.create.mockResolvedValue(SessionFactory.create());
+
+      await sut.callback(
+        { url: 'http://immich/auth/login?code=abc123', state: 'xyz789', codeVerifier: 'foo' },
+        {},
+        loginDetails,
+      );
+
+      expect(mocks.user.syncUsage).toHaveBeenCalledWith(user.id);
+      expect(mocks.user.update).toHaveBeenCalledWith(user.id, {
+        quotaSizeInBytes: 5_368_709_120,
+        updatedAt: expect.any(Date),
+      });
+    });
+
+    it('should sync unlimited quota on subsequent logins when the claim is -1', async () => {
+      const user = UserFactory.create({ oauthId: 'oauth-id', quotaSizeInBytes: 1_073_741_824 });
+
+      mocks.systemMetadata.get.mockResolvedValue(systemConfigStub.oauthWithStorageQuota);
+      mocks.oauth.getProfileAndOAuthSid.mockResolvedValue({
+        profile: OAuthProfileFactory.create({ sub: user.oauthId!, immich_quota: -1 }),
+      });
+      mocks.user.getByOAuthId.mockResolvedValue(user);
+      mocks.user.update.mockResolvedValue({ ...user, quotaSizeInBytes: null });
+      mocks.session.create.mockResolvedValue(SessionFactory.create());
+
+      await sut.callback(
+        { url: 'http://immich/auth/login?code=abc123', state: 'xyz789', codeVerifier: 'foo' },
+        {},
+        loginDetails,
+      );
+
+      expect(mocks.user.syncUsage).not.toHaveBeenCalled();
+      expect(mocks.user.update).toHaveBeenCalledWith(user.id, {
+        quotaSizeInBytes: null,
+        updatedAt: expect.any(Date),
+      });
+    });
+
+    it('should not sync the storage label on subsequent logins with the default claim', async () => {
+      const user = UserFactory.create({ oauthId: 'oauth-id', storageLabel: 'custom-label' });
+
+      mocks.systemMetadata.get.mockResolvedValue(systemConfigStub.oauthWithAutoRegister);
+      mocks.oauth.getProfileAndOAuthSid.mockResolvedValue({
+        profile: OAuthProfileFactory.create({ sub: user.oauthId!, preferred_username: 'idp-username' }),
+      });
+      mocks.user.getByOAuthId.mockResolvedValue(user);
+      mocks.session.create.mockResolvedValue(SessionFactory.create());
+
+      await sut.callback(
+        { url: 'http://immich/auth/login?code=abc123', state: 'xyz789', codeVerifier: 'foo' },
+        {},
+        loginDetails,
+      );
+
+      expect(mocks.user.update).not.toHaveBeenCalled();
+      expect(mocks.user.getByStorageLabel).not.toHaveBeenCalled();
+    });
+
+    it('should sync the storage label on subsequent logins when a custom claim is configured', async () => {
+      const user = UserFactory.create({ oauthId: 'oauth-id', storageLabel: 'custom-label' });
+
+      mocks.systemMetadata.get.mockResolvedValue({
+        oauth: { ...systemConfigStub.oauthWithAutoRegister.oauth, storageLabelClaim: 'immich_label' },
+      });
+      mocks.oauth.getProfileAndOAuthSid.mockResolvedValue({
+        profile: OAuthProfileFactory.create({ sub: user.oauthId!, immich_label: 'synced-label' }),
+      });
+      mocks.user.getByOAuthId.mockResolvedValue(user);
+      mocks.user.getByStorageLabel.mockResolvedValue(void 0);
+      mocks.user.update.mockResolvedValue({ ...user, storageLabel: 'synced-label' });
+      mocks.session.create.mockResolvedValue(SessionFactory.create());
+
+      await sut.callback(
+        { url: 'http://immich/auth/login?code=abc123', state: 'xyz789', codeVerifier: 'foo' },
+        {},
+        loginDetails,
+      );
+
+      expect(mocks.user.update).toHaveBeenCalledWith(user.id, {
+        storageLabel: 'synced-label',
+        updatedAt: expect.any(Date),
+      });
+    });
+
     it('should promote an existing user to admin if the role claim contains admin on login', async () => {
       const oauthId = 'oauth-id';
       const user = UserFactory.create({ isAdmin: false, oauthId });
@@ -1247,6 +1360,26 @@ describe(AuthService.name, () => {
       expect(mocks.user.update).not.toHaveBeenCalled();
     });
 
+    it('should not update claims on subsequent logins when they are absent from the profile', async () => {
+      const user = UserFactory.create({ oauthId: 'oauth-id', isAdmin: true, quotaSizeInBytes: 1_073_741_824 });
+
+      mocks.systemMetadata.get.mockResolvedValue(systemConfigStub.oauthWithStorageQuota);
+      mocks.oauth.getProfileAndOAuthSid.mockResolvedValue({
+        profile: OAuthProfileFactory.create({ sub: user.oauthId! }),
+      });
+      mocks.user.getByOAuthId.mockResolvedValue(user);
+      mocks.session.create.mockResolvedValue(SessionFactory.create());
+
+      await sut.callback(
+        { url: 'http://immich/auth/login?code=abc123', state: 'xyz789', codeVerifier: 'foo' },
+        {},
+        loginDetails,
+      );
+
+      expect(mocks.user.update).not.toHaveBeenCalled();
+      expect(mocks.user.syncUsage).not.toHaveBeenCalled();
+    });
+
     it('should re-evaluate the role claim for a user linked by email', async () => {
       const user = UserFactory.create({ isAdmin: false });
       const profile = OAuthProfileFactory.create({ immich_role: 'admin' });
diff --git a/server/src/services/auth.service.ts b/server/src/services/auth.service.ts
index dcfb60fc9..8d5da7b50 100644
--- a/server/src/services/auth.service.ts
+++ b/server/src/services/auth.service.ts
@@ -2,6 +2,7 @@ import { BadRequestException, ForbiddenException, Injectable, UnauthorizedExcept
 import { parse } from 'cookie';
 import { DateTime } from 'luxon';
 import { IncomingHttpHeaders } from 'node:http';
+import sanitize from 'sanitize-filename';
 import { LOGIN_DUMMY_HASH, LOGIN_URL, MOBILE_REDIRECT, SALT_ROUNDS } from 'src/constants.js';
 import { AuthSharedLink, AuthUser, UserAdmin } from 'src/database.js';
 import {
@@ -20,6 +21,7 @@ import {
   SignUpDto,
   mapLoginResponse,
 } from 'src/dtos/auth.dto.js';
+import { SystemConfig, defaults } from 'src/dtos/config.dto.js';
 import { UserAdminResponseDto, mapUserAdmin } from 'src/dtos/user.dto.js';
 import { AuthType, ImmichCookie, ImmichHeader, ImmichQuery, JobName, Permission } from 'src/enum.js';
 import { OAuthProfile } from 'src/repositories/oauth.repository.js';
@@ -39,8 +41,15 @@ export interface LoginDetails {
 
 interface ClaimOptions<T> {
   key: string;
-  default: T;
-  isValid: (value: unknown) => boolean;
+  isValid: (value: unknown) => value is T;
+  parse?: (raw: unknown) => T;
+}
+
+type OAuthClaimsConfig = Pick<SystemConfig['oauth'], 'defaultStorageQuota' | 'storageLabelClaim' | 'storageQuotaClaim'>;
+
+interface ParsedOAuthClaims {
+  storageLabel?: string | null;
+  quotaSizeInBytes?: number | null;
 }
 
 export type ValidateRequest = {
@@ -309,7 +318,7 @@ export class AuthService extends BaseService {
       idToken: oauthBearerToken,
     } = await this.oauthRepository.getProfileAndOAuthSid(oauth, url, expectedState, codeVerifier);
     const normalizedEmail = profile.email ? profile.email.trim().toLowerCase() : undefined;
-    const { autoRegister, defaultStorageQuota, storageLabelClaim, storageQuotaClaim, roleClaim } = oauth;
+    const { autoRegister, roleClaim } = oauth;
     this.logger.debug(`Logging in with OAuth: ${JSON.stringify(profile)}`);
     let user: UserAdmin | undefined = await this.userRepository.getByOAuthId(profile.sub);
 
@@ -333,7 +342,9 @@ export class AuthService extends BaseService {
     }
 
     // register new user
-    if (!user) {
+    if (user) {
+      user = await this.syncOAuthClaims(user, profile, oauth);
+    } else {
       if (!autoRegister) {
         this.logger.warn(
           `Unable to register ${profile.sub}/${normalizedEmail || '(no email)'}. User does not exist and auto registering is disabled. To enable set OAuth Auto Register to true in admin settings.`,
@@ -347,16 +358,7 @@ export class AuthService extends BaseService {
 
       this.logger.log(`Registering new user: ${profile.sub}/${normalizedEmail}`);
 
-      const storageLabel = this.getClaim(profile, {
-        key: storageLabelClaim,
-        default: '',
-        isValid: (value: unknown): value is string => typeof value === 'string',
-      });
-      const storageQuota = this.getClaim(profile, {
-        key: storageQuotaClaim,
-        default: defaultStorageQuota,
-        isValid: (value: unknown) => Number(value) >= 0,
-      });
+      const claims = this.parseOAuthClaims(profile, oauth, true);
 
       user = await this.createUser({
         name:
@@ -366,8 +368,8 @@ export class AuthService extends BaseService {
           normalizedEmail,
         email: normalizedEmail,
         oauthId: profile.sub,
-        quotaSizeInBytes: storageQuota === null ? null : storageQuota * HumanReadableSize.GiB,
-        storageLabel: storageLabel || null,
+        quotaSizeInBytes: claims.quotaSizeInBytes ?? null,
+        storageLabel: claims.storageLabel ?? null,
         isAdmin,
       });
     }
@@ -632,9 +634,84 @@ export class AuthService extends BaseService {
     return mapLoginResponse(user, token);
   }
 
-  private getClaim<T>(profile: OAuthProfile, options: ClaimOptions<T>): T {
-    const value = profile[options.key as keyof OAuthProfile];
-    return options.isValid(value) ? (value as T) : options.default;
+  private getClaim<T>(profile: OAuthProfile, options: ClaimOptions<T>): T | undefined {
+    const raw = profile[options.key as keyof OAuthProfile];
+    const value = options.parse ? options.parse(raw) : raw;
+    return options.isValid(value) ? value : undefined;
+  }
+
+  private parseOAuthClaims(profile: OAuthProfile, oauth: OAuthClaimsConfig, useDefaults: boolean): ParsedOAuthClaims {
+    const { defaultStorageQuota, storageLabelClaim, storageQuotaClaim } = oauth;
+    const claims: ParsedOAuthClaims = {};
+
+    const storageLabel = this.getClaim(profile, {
+      key: storageLabelClaim,
+      isValid: (value): value is string => typeof value === 'string',
+    });
+
+    if (useDefaults) {
+      claims.storageLabel = storageLabel || null;
+    }
+    // Default claim (preferred_username) is registration-only; login sync is opt-in.
+    else if (storageLabelClaim !== defaults.oauth.storageLabelClaim && storageLabel !== undefined) {
+      claims.storageLabel = this.formatStorageLabel(storageLabel);
+    }
+
+    const storageQuota = this.getClaim(profile, {
+      key: storageQuotaClaim,
+      parse: Number,
+      isValid: (value): value is number =>
+        typeof value === 'number' && Number.isFinite(value) && (value === -1 || value >= 0),
+    });
+
+    if (storageQuota !== undefined) {
+      claims.quotaSizeInBytes = storageQuota === -1 ? null : storageQuota * HumanReadableSize.GiB;
+    } else if (useDefaults) {
+      claims.quotaSizeInBytes =
+        defaultStorageQuota === null || defaultStorageQuota === -1 ? null : defaultStorageQuota * HumanReadableSize.GiB;
+    }
+
+    return claims;
+  }
+
+  private formatStorageLabel(label: string): string | null {
+    if (!label) {
+      return null;
+    }
+
+    return sanitize(label.replaceAll('.', ''));
+  }
+
+  private async syncOAuthClaims(user: UserAdmin, profile: OAuthProfile, oauth: OAuthClaimsConfig): Promise<UserAdmin> {
+    const claims = this.parseOAuthClaims(profile, oauth, false);
+    const updates: {
+      storageLabel?: string | null;
+      quotaSizeInBytes?: number | null;
+    } = {};
+
+    if (claims.storageLabel && claims.storageLabel !== user.storageLabel) {
+      const duplicate = await this.userRepository.getByStorageLabel(claims.storageLabel);
+
+      if (duplicate && duplicate.id !== user.id) {
+        this.logger.warn(`Unable to sync OAuth storage label for user ${user.id}: label already in use`);
+      } else {
+        updates.storageLabel = claims.storageLabel;
+      }
+    }
+
+    if (claims.quotaSizeInBytes !== undefined && claims.quotaSizeInBytes !== user.quotaSizeInBytes) {
+      updates.quotaSizeInBytes = claims.quotaSizeInBytes;
+    }
+
+    if (Object.keys(updates).length === 0) {
+      return user;
+    }
+
+    if (updates.quotaSizeInBytes) {
+      await this.userRepository.syncUsage(user.id);
+    }
+
+    return this.userRepository.update(user.id, { ...updates, updatedAt: new Date() });
   }
 
   private getRoleClaim(profile: OAuthProfile, roleClaim: string): 'admin' | 'user' | undefined {