Basel-Stadt Inheritance Tax Forms & Deadlines
Last updated: 26 Oct 2025 • Author: Alexander Foelsche CPA (US), WP (DE), RE (CH)
Basel-Stadt Inheritance Tax — Forms & Deadlines
One-stop page for Basel-Stadt inheritance tax filing: who must file, which forms you need, due dates and extensions, how to file and pay, penalties and interest, and practical checklists.
Who must file?
Core forms & where to get them
Basel-Stadt forms & documents
- Erbschaftssteuererklärung — inheritance tax return listing assets, debts, and beneficiaries.
- Erbenverzeichnis — heirs/beneficiaries list with relationships and contact details.
- Bewertungen/Gutachten — appraisals and statements for real property, bank accounts, and securities as of the date of death.
- Vollmacht — Power of Attorney if a representative files for the estate or heirs.
- Steuerbescheinigung/Unbedenklichkeitsbescheinigung — tax clearance/certificate after assessment/payment for registry/banking purposes.
Steuerverwaltung Basel-Stadt — Erbschaftssteuer
Forms and instructions are issued by the canton; the city offices/Grundbuch may assist where relevant.
Attachments commonly required
- Death certificate and civil-status/family register extract.
- Will or inheritance contract, probate/appointment documents (if any).
- Bank/portfolio statements and property valuations as of date of death.
- Relationship proofs to claim exemptions or reduced rates.
Follow the notice from the Steuerverwaltung for the full list of required attachments.
Deadlines, extensions & installments
| Item | When due | Notes |
|---|---|---|
| Inheritance tax return (Erbschaftssteuererklärung) | 6 months after date of death | File with the competent Basel-Stadt office based on the decedent’s last residence or Basel-Stadt-situs property. |
| Extension to file | On written request before the deadline | Provide reasons (e.g., pending appraisals). Extension to file does not extend time to pay once assessed. |
| Payment of tax | As stated on the assessment notice | The Steuerverwaltung typically sets a payment deadline (often ~30 days). Interest on arrears accrues after the due date. |
| Provisional payments | Any time before assessment | Heirs may make on-account payments to reduce interest exposure; reference the estate file number if available. |
How to file & pay
Submission
Inheritance returns are usually filed on paper or as instructed by the Steuerverwaltung Basel-Stadt. Some correspondence may be handled electronically if agreed. Always follow the address and instructions on your notice.
Payment, penalties & interest
- Payment: by the deadline stated on the assessment (commonly ~30 days).
- Interest on arrears: accrues after the due date on unpaid amounts.
- Administrative fines: possible for late filing, under-reporting, or non-disclosure.
Sanctions are applied case-by-case under cantonal rules.
Practical checklists
Before filing
- Confirm domicile and identify Basel-Stadt-situs assets (for nonresidents).
- Collect valuations and statements as of the date of death.
- Compile the heirs list and relationship proofs for exemptions.
- Request land-registry extracts (Grundbuch) for Basel-Stadt real estate where needed.
When extending
- Submit a written extension request before the 6-month deadline with reason and estimated timeline.
- Consider a provisional payment to limit interest.
- Track payments so they can be credited on assessment.
FAQs
When is the Basel-Stadt inheritance tax return due?
Generally within six months after the date of death. The authority may grant more time on written request, but payment remains due by the date shown on the assessment, and interest applies to late payment.
How do I get more time to file?
Apply in writing to the Steuerverwaltung Basel-Stadt before the deadline. Explain the reason (e.g., pending appraisals). An approved filing extension does not extend time to pay.
Where do I get the forms?
Forms are provided by the Steuerverwaltung Basel-Stadt. Contact details appear on your notice; general information is available at steuerverwaltung.bs.ch.
What must be attached?
Death certificate, civil-status/family register extract, will or inheritance contract, appraisals, bank and portfolio statements, real property valuations, and relationship proofs to claim exemptions or reduced rates.