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Back-pay

Back-pay calculator

A new CAO with retroactive effect? This is what you get paid on top, gross and net.

When a CAO is agreed after the date its pay rise takes effect, your employer pays the difference for the months already worked in one go. Pick your CAO and position, or enter your old and new salary yourself.

Your situation

Net back-pay€450.95
Gross back-pay€777.60

Special rate: 42.008%. The rate belongs to an annual wage of €40,435 (salary × 12 with holiday allowance and year-end bonus).

Retroactive months

MonthOldNewDifference
April 2026€3,000.00€3,120.00€120.00
May 2026€3,000.00€3,120.00€120.00
June 2026€3,000.00€3,120.00€120.00
July 2026€3,000.00€3,120.00€120.00
August 2026€3,000.00€3,120.00€120.00
September 2026€3,000.00€3,120.00€120.00

How it is calculated

  • Salary difference over 6 monthssource€720.00
  • Plus: holiday allowance on the difference€57.60
  • Back-pay gross€777.60
  • Less: wage tax at the special rate (42.008%)source-€326.65
  • Back-pay net€450.95

Estimate. The employer withholds wage tax using the special-payments table (tabel bijzondere beloningen) or the recalculation method; the table rounds per wage band, so your payslip may differ slightly. Your income tax return settles the whole year.

Back-pay: frequently asked questions

How is back-pay taxed in the Netherlands?

Back-pay is wage for earlier months paid out at once. The employer withholds wage tax with the special-payments table (tabel bijzondere beloningen): one rate that belongs to your annual wage. According to the Belastingdienst Kennisgroep Loonheffingen the employer may also use the recalculation method. Any difference with the tax for the whole year is settled in your tax return.

What does a back-pay example look like?

Say you earn €3,000 gross per month and the CAO adds 4% from April 2026, paid in October. You get 6 months × €120.00 = €720.00 plus 8% holiday allowance €57.60, together €777.60 gross. The special rate for an annual wage of €40,435 is 42.01%, so €326.65 wage tax and €450.95 net.

Do I also get holiday allowance on the back-pay?

Yes: holiday allowance is a percentage of your salary, so a higher salary over past months also means more holiday allowance. If it was already paid, the difference usually comes with the back-pay. The same goes for a year-end bonus calculated as a percentage of salary.

Why is the rate on my back-pay so high?

The special rate is your marginal rate: the tax on each extra euro on top of your annual wage. Besides the bracket rate, the general tax credit and, above a certain income, the labour tax credit shrink as you earn more. That makes the rate higher than the bracket rate itself.