Box 3 and provisional tax assessments: apply before year-end

Why the valuation date matters

The standard box 3 calculation uses the asset position on 1 January. Money still in your bank account on that date generally remains part of your bank balances, even if reserved for income tax. An ordinary income tax liability cannot be deducted as a box 3 debt. Paying an assessment before the valuation date means the money is no longer in the account.

Apply for an appropriate assessment in time

The Box 3 policy decision requires a provisional-assessment request eight weeks before calendar year-end. For 2026, 4 November is therefore an important date to work towards. This request route applies while the return for the relevant year has not yet been submitted. A different deadline applies to a submitted tax return: thirteen weeks. Base your request on a supported estimate of expected tax and check which route applies to you.

What if processing takes too long?

Even a timely request may be processed so late that payment before the valuation date is no longer reasonably possible. Subject to conditions, the concession then allows bank balances to be reduced by the tax due on the assessment that was not issued in time. The reduction is limited by the final amount due and by available bank balances. It cannot produce a negative box 3 bank balance. Simply submitting a request does not create an unconditional deduction.

Standard and actual returns remain different

The concession adjusts the value of bank balances for the standard calculation. Under the box 3 counter-evidence rules, actual returns still use the interest genuinely received, without this adjustment. A lower bank balance in the standard calculation therefore does not produce an equivalent saving in every case. Assess the effect using your overall assets, tax position and available liquidity.

Keep a complete file

Retain your calculation, submitted request, acknowledgement and subsequent assessment and payment evidence. Check that the figures continue to reflect your expected income. This helps explain any reduction claimed later.

Oudshoorn can review your provisional assessment and its connection with your tax return. The aim is appropriate treatment of your actual obligations while retaining enough funds to meet the payment.

More information from Oudshoorn

• Income tax returns
• Tax advice

Sources and background

• Belastingdienst – belastingschulden