In Basel-Stadt, wealth tax is filed together with the individual income tax return. The canton supports e-filing via BalTax Online / eSteuern as well as traditional paper filing. As a city canton, Basel-Stadt applies a unified cantonal/communal rate rather than municipal multipliers.

Filing Timeline (Typical Cycle)

1. January–February: Basel-Stadt issues filing invitations and opens the BalTax Online / eSteuern modules for the new tax year.
2. Ordinary due date (private individuals): Typically 31 March of the following year.
3. Companies / self-employed: Company returns are generally due by 30 June (exact dates per the tax office communication).
4. Extension window: Extensions can usually be requested online or in writing; in practice, private individuals can often obtain extensions up to 31 December of the filing year.
5. Assessment & billing: Provisional bills may be issued; final assessments follow review. Late payments accrue interest.

Always verify the current-year dates on the Basel-Stadt tax administration portal before filing.

How to File in Basel-Stadt

1) e-Filing via BalTax Online / eSteuern (recommended)

• Log in to BalTax Online (eSteuern Basel-Stadt) using the credentials or access code provided with your filing invitation.
• Complete income schedules and the 31 December wealth statement (assets, liabilities, allowances).
• Upload supporting documents (bank and securities statements, valuation extracts) in PDF or other accepted formats.
• Submit your return electronically; in many cases no separate paper signature is required once the online submission is confirmed.

2) Paper Return

• Use the official forms for the relevant tax year (sent by post or generated via BalTax as a printout).
• Attach copies of statements; keep originals for your own records.
• Sign the return (or signature sheet) and send it to the address indicated on the filing invitation or as instructed by the tax office.

Extensions

If you cannot file by the ordinary due date, request an extension via the Basel-Stadt eSteuern portal or in writing. Standard extensions within the same calendar year are usually granted as a matter of course; extensions beyond year-end are more restrictive.

• Request before due date: Submit the extension request by 31 March (or by the printed deadline) to avoid reminders and estimated assessments.
• Online extension: Use the eSteuern / BalTax Online service for quick processing of extension requests.
• Maximum extension: For many individual taxpayers, an extension up to 31 December of the filing year is possible; beyond that, approval requires compelling reasons and often advance payments.
• Advisor mandate: A tax representative can request and monitor extensions on your behalf.
• Penalties: Late or missing returns can trigger reminder fees, fines, and discretionary (estimated) assessments.

Provisional Payments, Interest & Adjustments

Basel-Stadt issues provisional instalments based on prior assessments or estimated tax factors. You may request adjustments if your income or wealth changes significantly. After filing and review, a final bill is issued. Late payments accrue interest at the cantonal rate.

• Payment references: Use the QR-bill or payment reference printed on each invoice.
• Partial payments: Typically allowed; keep payment confirmations and invoices for reconciliation.
• Objections (Einsprache): If you disagree with the assessment, file a written objection within the deadline shown on the assessment notice.

Nonresidents with Basel-Stadt-Situs Assets

Nonresidents owning Basel-Stadt real estate or business assets generally file a limited return covering Swiss-situs income and wealth. A Swiss correspondence address or tax representative is often required. See the Nonresident Guide.

Document Checklist (Wealth Section)

Prepare and upload/retain the following to support your 31 December wealth statement:

Annual Changes

Forms, BalTax Online modules, deadlines, and the Basel-Stadt tariff are updated annually. Confirm the current-year requirements and due dates on the official Basel-Stadt tax administration portal before submitting your return.