The interest deduction is automatically subtracted from your yearly tax and listed in your yearly declaration, if you fulfil the requirements, meaning you’re likely to get it back as a lump sum when tax season rolls around next April. This literally translates as “tax equalisation”, and it’s a way you can spread your tax rebate for interest costs out over a year, lowering your mortgage costs each month rather than of getting a lump sum in the form of a tax rebate during tax declaration season. If your application is accepted, the Tax Agency will tell your employer to subtract less tax from your payslip each month, effectively meaning that you get your tax rebate for interest costs back in your monthly pay instead of getting it paid out all at once.