Nonresidents are subject to Basel-Stadt wealth tax on assets that are économiquement liés au canton. In practice, this limited tax liability focuses on immobilier et les actifs des entreprises located in Basel-Stadt, while foreign portfolios and movable property held abroad are not taxed in the canton.

This guide summarises the scope, valuation rules, and compliance requirements for the 2025 tax year for nonresident individuals with assets in Basel-Stadt.

1. Champ d'application de la responsabilité fiscale limitée

A nonresident becomes liable for wealth tax in Basel-Stadt if they hold any of the following:

• Residential or commercial real estate situated in the canton of Basel-Stadt
• Land or development sites located within Basel-Stadt
• Permanent establishments or fixed places of business (e.g., offices, shops, hotels, restaurants) in the canton
• Business assets allocated to a Basel-Stadt branch or place of effective management

Assets outside Switzerland — such as foreign securities, overseas real estate, and non-Swiss bank accounts — are excluded from the Basel-Stadt wealth-tax base, though they may remain relevant in the country of residence for rate or reporting purposes.

2. Base d'évaluation

Basel-Stadt applies cantonal valuation rules that are harmonised with federal law but implemented via its own practice:

• Immobilier : Valeur fiscale cantonale (Steuerwert), généralement en dessous de la valeur du marché
• Titres et actifs bancaires : Valeur fiscale de fin d'année basée sur les listes officielles de valeurs fiscales fédérales et les taux de change
• Fonds de commerce : Book or fair value according to Swiss accounting standards, with Basel-Stadt adjustments where applicable
• Actifs de pension : 2nd pillar and pillar 3a pension capital is usually exempt from wealth tax until payout

Le Steuerwert for real estate in Basel-Stadt reflects a fraction of market value and takes account of location, use, and building characteristics. For detailed valuation methodology in this canton, see Règles d'évaluation.

3. Répartition de la dette

Debt allocation for nonresidents in Basel-Stadt follows the Swiss principle of lien économique combinée à l'allocation proportionnelle :

• Mortgages secured on Basel-Stadt property are deductible from the wealth-tax value of that property.
• Other debts are deductible only to the extent they can be economically tied to Swiss assets or allocated proportionally.
• If the taxpayer owns property in multiple Swiss cantons, total debt is allocated among cantons according to the relative taxable values of those assets.

Interest on debt is relevant for income tax and is split between jurisdictions based on Swiss-sourced assets and income, including allocation across cantons.

4. Allocations et exonérations

Nonresident taxpayers in Basel-Stadt generally do pas have access to the full range of personal allowances and deductions granted to residents. However, certain items are typically excluded from the wealth-tax base:

• Tax-exempt pension capital (occupational and pillar 3a) until withdrawal
• Biens de consommation courante et effets personnels
• Exemptions techniques de moindre importance requises en vertu de la loi cantonale harmonisée

For nonresidents, the effective burden is mainly driven by the property’s Steuerwert, the progressive Basel-Stadt wealth tax scale, and debt allocation.

5. Traités de double imposition

En vertu des conventions de double imposition conclues par la Suisse, l'imposition des biens immobiliers is generally assigned to the state where the property is located. As a result, Basel-Stadt retains the right to tax real estate and related business premises situated in the canton, even if the owner is resident abroad.

L'aide est alors généralement accordée dans le pays de résidence :

• Exemption avec progression, ou
• Crédit d'impôt étranger for Basel-Stadt wealth tax against home-country wealth or property taxes.

Always check the specific treaty between Switzerland and your country of residence and retain Basel-Stadt tax assessments and receipts as proof of Swiss tax paid.

6. Représentant fiscal suisse

Les non-résidents doivent généralement fournir un Adresse de correspondance en Suisse or appoint a tax representative when dealing with the Basel-Stadt tax authorities.

• Les fiduciaires, les conseillers fiscaux ou les avocats suisses peuvent agir en tant que mandataires.
• La correspondance officielle et les évaluations sont rédigées en allemand.
• Le recours à un représentant permet de gérer les délais, les questions linguistiques et les éventuels recours ou objections.

7. Dépôt et conformité

Nonresident owners of property or business assets in Basel-Stadt file a déclaration fiscale suisse limitée covering Swiss-situs income and wealth. The wealth tax portion focuses on net taxable assets situated in Basel-Stadt as at 31 December.

• Confirmation officielle de la Steuerwert
• Confirmations d'hypothèques et de prêts en fin d'année
• Relevés des revenus et dépenses locatifs pour les biens loués
• Business balance sheet and asset schedules where a Basel-Stadt permanent establishment exists

Filing deadlines generally align with those for Basel-Stadt residents. Extensions are typically available upon request, often submitted via a Swiss representative.

8. Example — Nonresident City Apartment Owner

Profil : Resident of France, owns an apartment in Basel-Stadt.

• Steuerwert : 1 050 000 CHF
• Mortgage balance: CHF 700,000
• Basel-Stadt multiplier / effective factor (illustrative): 1.70 (170 % of simple tax)

Étape 1 - Patrimoine net imposable : CHF 1,050,000 − CHF 700,000 = CHF 350,000
Étape 2 - Impôt sur la fortune simple (taux progressif illustratif) : 3.2‰ of CHF 350,000 = CHF 1,120
Step 3 — Applying factor: CHF 1,120 × 1.70 = CHF 1,904
→ Indicative effective burden of about 0.54 % of net taxable wealth (illustrative only; actual rates depend on year and specific rules).

9. Ending Basel-Stadt Tax Liability

Wealth tax liability in Basel-Stadt normally ends when the property or business assets located in the canton are sold, transferred, or otherwise disposed of. A déclaration fiscale limitée finale doit être déposée et les éventuels impôts sur la fortune et sur les plus-values immobilières doivent être réglés.

The Basel-Stadt tax office should be notified promptly of the disposal to avoid continued assessments based on outdated ownership data.

10. Conseils de planification pour les non-résidents

• Obtain an estimate of the Basel-Stadt Steuerwert and effective wealth tax factor before acquiring property.
• Align mortgage structure and debt allocation with your wider cross-border wealth and estate planning.
• Review how Basel-Stadt wealth tax interacts with home-country rules and any applicable double tax treaties.
• Faites appel à un représentant fiscal suisse pour gérer les déclarations, assurer la coordination avec le conseiller de votre pays d'origine et traiter la correspondance en langue allemande.