In Basel-Stadt, wealth tax is levied on a taxpayer’s net wealth (Reinvermögen): worldwide assets minus deductible liabilities and any applicable tax-free allowances. The canton uses a progressive wealth tax scale (Tarif A and B), so the determination of taxable net wealth after allowances and deductions has a direct impact on the overall burden.

This overview reflects current practice under the Gesetz über die direkten Steuern des Kantons Basel-Stadt (StG BS), the implementing ordinances, and the guidance provided in the Wegleitung zur Steuererklärung Basel-Stadt and the cantonal tariff book.

Personal Allowances

Basel-Stadt grants wealth tax allowances (Freibeträge) that reduce taxable net wealth. The allowance depends on the applicable tariff (single vs. married) and the number of minor children. The relevant circumstances are those in place on 31 December of the tax year.

The allowance levels shown (CHF 75,000 / CHF 150,000 plus CHF 15,000 per minor child) reflect the cantonal wealth tax framework in force for recent tax years. Exact figures are specified in the Basel-Stadt tariff book and may be updated periodically.

Debt Deductions

Basel-Stadt levies wealth tax on net wealth, so legally enforceable, clearly documented liabilities as of 31 December can be deducted from gross assets. Typical deductible debts include:

• Mortgage balances on Swiss and foreign real estate in private ownership
• Bank loans, investment credit lines and margin loans
• Private loans, provided there is a written agreement and interest documentation
• Outstanding federal, cantonal and municipal tax liabilities

Debts denominated in foreign currencies are translated into CHF using the official year-end exchange rates recognised by the authorities (generally those issued by the Federal Tax Administration).

Contingent or informal obligations (e.g. guarantees, sureties or letters of comfort) are not deductible until they crystallise into an actual, enforceable liability.

Pension Assets & Retirement Accounts

Certain retirement assets are exempt from wealth tax in Basel-Stadt as long as they remain within the pension framework. In particular:

• Occupational pension assets in Swiss 2^nd pillar schemes (berufliche Vorsorge / BVG) are excluded from taxable wealth until pay-out.
• Tied individual retirement accounts (pillar 3a) are likewise not subject to wealth tax.

Non-tied savings and investment products (pillar 3b) remain fully taxable. Pension buy-ins and pillar 3a contributions primarily reduce income tax; they impact wealth tax only to the extent that assets shift from taxable private accounts into exempt pension vehicles.

Valuation Adjustments

Basel-Stadt generally values assets at market value (Verkehrswert) as at year-end, subject to specific rules for certain categories which may reduce taxable wealth compared to simple market value:

• Household effects: normal household goods and personal belongings (Hausrat und persönliche Gebrauchsgegenstände) are exempt from wealth tax.
• Securities and funds: listed securities are valued at their official year-end prices; many collective investment schemes have specific taxable values published by the authorities.
• Unlisted business interests: typically valued using practice methods combining income-based and asset-based approaches, in line with Basel-Stadt and Swiss tax conference guidance, often resulting in a taxable value below pure book equity.
• Real estate: income-producing properties are often valued using an income value (capitalisation of rental income), while self-occupied properties are valued closer to real value (indexed insurance value plus land component based on cantonal land value tables).
• Life and annuity policies: policies with a surrender value are taxed at that value; non-surrenderable claims generally fall outside the wealth tax base.
• Cryptocurrencies and digital assets: usually valued at the official year-end prices published by the Federal Tax Administration.

Marital Property & Family Context

Married couples and registered partners living in an undissolved partnership are generally taxed jointly in Basel-Stadt. Their income and wealth are aggregated, and tariff B (with the higher CHF 150,000 allowance) is applied to their combined net wealth.

The assets of minor children under parental authority are normally attributed to the parents’ tax return for wealth tax purposes; the per-child allowance is granted on this basis. Where children have substantial own assets or special arrangements, separate treatment may apply.

Gifts, inheritances and extraordinary inflows are included in taxable wealth as of 31 December, unless they qualify for specific exemptions (for example, certain pension or insurance benefits). Separate Basel-Stadt rules govern inheritance and gift tax and should be considered alongside wealth tax planning.

Documentation & Compliance

The Basel-Stadt tax administration expects comprehensive documentation for both assets and liabilities declared for wealth tax, such as:

• Year-end bank and custody statements for cash, securities and fund holdings
• Mortgage and loan balance confirmations as at 31 December
• Written agreements and interest evidence for private loans
• Pension fund statements (2^nd pillar) and pillar 3a account overviews
• Valuation reports or tax values for real estate and private company interests, where relevant

Ensuring that figures in the income tax and wealth tax sections of the return are consistent (for example, for securities portfolios or rental properties) helps avoid follow-up questions and assessment adjustments.

Planning Insights

• Basel-Stadt applies progressive wealth tax tariffs (different brackets for tariffs A and B). Managing taxable net wealth around key bracket thresholds can generate recurring savings, especially for higher-net-worth households.
• For taxpayers with modest income but significant assets, Basel-Stadt provides wealth tax relief where the combined tax on wealth and investment income exceeds a certain share of the actual yield. In such cases, the wealth tax can be reduced to a percentage cap of taxable wealth, subject to conditions.
• Mortgages and investment loans can lower taxable net wealth, but interest costs reduce overall after-tax returns and affect income tax. Any restructuring should be modelled across both wealth and income taxes.
• Large holdings of low-yield or non-productive assets (excess cash, art, collectibles) above the allowance thresholds can disproportionately increase wealth tax. Reallocating into diversified portfolios or tax-advantaged pension vehicles may improve both risk/return and tax outcomes.
• Intra-family planning (gifts, loans, early transfers of real estate or business interests) can shift wealth tax exposure between generations. Only properly documented arrangements are recognised for tax purposes and they may trigger inheritance or gift tax, so coordinated advice is recommended.