Provisional Tax Assessment
A provisional tax assessment is an advance that the tax authorities levy (or refund) based on an estimate of your income. This can be a provisional refund – for example if you have mortgage interest deductions – or a provisional payment if you expect additional income. The tax authorities often base the provisional assessment on last year's return. You can also request or modify a provisional assessment yourself via Mijn Belastingdienst. After your final return, everything is settled: if you overpaid, you get money back. If you underpaid, you need to pay the difference.
Example
You have a mortgage and deduct €6,000 in interest annually. You request a provisional refund. The tax authorities pay you approximately €185 per month (€6,000 × 36.97% / 12). This way you don't have to wait until after filing your return to get your tax benefit.
Why does this matter?
A provisional assessment can significantly improve your cash flow. Instead of getting one large refund after filing, you receive monthly advances. This is especially useful for mortgage interest deductions or high healthcare costs.