How can I apply for an extension of the deadline for filing a tax return in Switzerland?

Overview of renewal options

In Switzerland, it is possible in all cantons to apply for an extension of the deadline for filing a tax return. Most cantons grant these extensions generously and often at no additional cost.

Basic requirements for renewals

Timely application

• Most important rule: Application must be submitted before the original deadline
• Too late: After the deadline, it becomes more difficult and often requires a fee
• exemptions: In case of special circumstances (illness, emergency), also possible retrospectively

No justification required

• Most cantons do not require detailed reasons
• A simple application for an extension is usually sufficient
• Repeated renewals may result in inquiries

Extension periods by canton

Standard extension (first extension)

• zurich: until September 30 (automatically)
• berne: until September 30
• aargau: until September 30
• Basel-City: by September 30 (automatically if submitted online)
• St. Gallen: until September 30
• luzern: until September 30

Further extensions possible

• Second extension: usually until November 30
• Third extension: until December 31 (approved less frequently)
• Special circumstances: also possible beyond the end of the year

Divergent cantons

• geneva: until September 30, further until December 31
• vaud: standard until September 30
• ticino: until September 30, often longer
• wallis: flexible handling depending on the situation

Application process by canton

Online procedure (preferred)

zurich

• portal: “eTax Zurich”
• proceedings: Automatic extension when registering online
• deadline: until September 30 without further request
• expenses: free

berne

• portal: “BetaX”
• proceedings: Fill out the online form
• corroboration: automatic email confirmation
• expenses: free

Basel-City

• portal: “eTaxes Basel-City”
• specificity: Automatic extension until September 30 when used online
• Further extension: separate application required

Written requests

Informal letter

Simple letter with the following information:

• Full name and address
• Tax number or AHV number
• tax year
• Requested extension period
• Date and signature

Sample text:

Dear ladies and gentlemen,

I hereby request an extension of the deadline for submission
my 2024 tax return until September 30, 2025.

Name: [your name]
Address: [your address]
Tax ID: [if known]

sincerely
[signature]

Official forms

• Many cantons offer special forms
• Download mostly on the tax administration website
• Fill out and send by post or email

Telephone applications

availability

• Smaller cantons: often possible
• Larger cantons: usually only in writing or online
• Personal advice: Telephone numbers on cantonal websites

tactic

• Have your tax number and personal data ready
• State the desired extension period
• Request confirmation in writing

Automatic renewals

Cantons with automatic extension

Some cantons grant automatic extensions under certain conditions:

zurich

• Automatically until September 30 if you register online
• No further action required
• Email reminder

Basel-City

• Automatically until September 30 when used online
• Only when using the online portal for the first time

Requirements for automatic renewal

• Registration in the online portal before the original deadline
• No previous omissions
• Complete profile data stored

Renewal costs

Free renewals

• First extension: free of charge in all cantons
• Until September 30: usually without fees
• Online applications: generally free

Paid renewals

• After September 30: some fees
• Multiple extensions: often subject to a fee from the third
• fees: 20-100 CHF depending on canton and situation

Sample charges

• berne: second extension 50 CHF
• aargau: third extension 30 CHF
• St. Gallen: Extension beyond November 75 CHF

Special situations

Illness or emergencies

• Medical certificate: in case of prolonged illness
• Fair treatment: subsequent extensions are also possible
• No fees: in case of proven emergencies

Complex tax cases

• Self-employed: longer extensions are often possible
• International issues: additional time to obtain foreign documents
• Inheritance cases: special rules in the event of death

First-time tax liability

• Fair treatment: for the first tax returns
• Counseling appointments: free support available
• Longer deadlines: often possible until the end of the year

Extension for tax advisors

Professional representatives

• Flat rate extensions: for trustees and tax advisors
• Until March 31 of the following year: often possible
• Collective powers of attorney: for several clients at the same time

prerequisites

• Professional qualification: registered tax advisors
• power of attorney: written authorization required
• Early application: usually by the original deadline

Digital tools

Reminder services

• email notifications: automatic reminders
• SMS service: available in some cantons
• App notifications: for tax administrations' mobile apps

Online portals overview

• zurich: eTax Zurich
• berne: BetaX
• aargau: eTaxes Aargau
• Basel-City: eTaxes Basel-City
• St. Gallen: eTAX St. Gallen

Avoid common mistakes

Too late application

• problem: Request after the deadline
• solution: Set calendar entries and reminders
• emergency: immediate contact with the tax administration

Incomplete information

• problem: missing tax number or address
• solution: provide all documents before submitting an application
• post-processing: may cause delays

Wrong contacts

• problem: Request sent to the wrong authority
• solution: Check the website of the responsible tax administration
• relaying: mostly automatic, but time-consuming

Practical tips

Early planning

• Start of the year: think about an extension as early as January
• Complex cases: arrange professional help in good time
• Collect receipts: continuous documentation throughout the year

Communication with authorities

• Polite and precise: provide clear information
• Request confirmation: written confirmation of extension
• Keep contact details up to date: be available for inquiries

backup plans

• Plan B: check alternative extension options
• Professional help: Tax advisors as an emergency solution
• Partial submission: incomplete explanation as an interim solution

Legal bases

Statutory basis

• Cantonal tax laws: individual regulations
• Tax procedural law: uniform basic principles
• Discretionary: Authorities have a certain degree of flexibility

Complaint options

• rejections: can be appealed
• Complaints Board: Cantonal Tax Appeal Commission
• deadlines: usually 30 days for objections

Extension vs. early submission

Benefits of early filing

• Faster refund: with credit
• Less stress: no time shortage
• Better advice: more time for inquiries

When extension makes sense

• Missing documents: important documents not yet available
• Complex issues: sufficient time for correct processing
• Professional overload: edit in quieter times

conclusion

Applying for an extension of the deadline for filing a tax return in Switzerland is easy and usually free of charge. Timely application before expiry of the original deadline is decisive. Preferably use online procedures, as these often enable automatic renewals and are processed more quickly. In special circumstances, tax administrations are usually accommodating and also grant exceptional extensions.