A Dutch tax position clarifies when the allocation of home-loan parts between Box 1 and Box 3 becomes fixed. Once the purchase-year assessment is irrevocable, the allocation generally remains in place until relevant circumstances concerning the home change. That can affect mortgage-interest treatment in later years.
Why this matters
A lender may show one mortgage balance, while the tax file records separate loan histories. One loan part may qualify as existing own-home debt in Box 1. Another may fall in Box 3. That split affects the household cash forecast. A founder may use that forecast when deciding on salary, dividends, a renovation, or a company cash buffer. The purchase-year return, loan papers, and final assessment should tell the same story.
Example
The official case concerns two interest-only loans of €400,000 for one home. Both loans are connected to the purchase. Only €400,000 qualifies for transitional treatment as existing own-home debt. The taxpayer can place one full loan in Box 1 and the other in Box 3 in the purchase-year return. The allocation can change while that assessment remains open. Once it is irrevocable, the labels cannot simply be swapped for a better later tax result. Refinancing alone does not automatically restart the analysis.
XTROVERSO tips
- Find the purchase-year return. Locate the income-tax return for the year you bought the current home. Note which loan parts appear in Box 1 and Box 3.
- Check whether the assessment is final. Find the purchase-year assessment and record when it became irrevocable. Keep any objection or appeal documents with it.
- Match the records. Compare the return with loan offers, the notarial completion statement, and lender records. Loan-part numbers and amounts should match.
- Keep a loan timeline. Record repayments, increases, renovations, refinancing, moves, and ownership changes. Keep invoices and proof of how borrowed funds were used.
- Check the cash plan. See whether a dividend, salary decision, renovation, or business investment assumes a different mortgage allocation. Use the recorded tax position until a review supports different treatment.
Need to check which mortgage choices remain open before a private or company cash decision? We can review the file with you
The data, sourcing, and analysis behind this article were conducted by Linda Pavan. AI was not used to identify sources, build the factual basis, or produce the analytical judgment contained here. AI was used only as a drafting aid. The final English text was personally reviewed, edited, and approved by Linda Pavan before publication.
References
- KG:051:2026:3 Terugkomen op keuze lening die als bestaande eigenwoningschuld in box 1 is aangegeven | Kennisgroepen Belastingdienst
- Belastingdienst - Maximum own-home debt and the Box 3 remainder
- Belastingdienst - Transitional treatment for pre-2013 debt and later loan increases
- Wettenbank - Statutory own-home debt, repayment and moving rules
- Wettenbank - Policy basis for allocation by taxpayer intention
- Rechtspraak - Historical-causal connection and documentary proof


