Fraudulent emails are currently in circulation that are falsely sent on behalf of the FTA. These emails ask you to update your tax details or contain purported surveys designed to gather personal information. Official emails from the FTA are sent exclusively from addresses ending in @admin.ch or a corresponding subdomain of @***.admin.ch. Please ignore any suspicious messages, do not open any attachments, do not click on any links and do not disclose any personal details. Thank you for your vigilance.

Further measures can be found on the website of the National Cyber Security Centre (NCSC).
National Cyber Security Centre (NCSC)

Swiss tax at source

Tax at source rates for wages and other income of foreign employees.

As English is not one of Switzerland's official languages, only the most important information is translated into English. Please refer to the German, French or Italian original version.