Norway has two tax bases, and mixing them up costs you
Almost every mistake in a Norwegian take-home calculation comes from the same place: treating Norway as if it taxed one number. It taxes two, computed differently, and a deduction only touches one of them.
The two bases
Alminnelig inntekt, ordinary income, is your pay less the minstefradrag (46% of pay, capped at NOK 95,700) and the personfradrag of NOK 114,540. It carries a flat 22%.
Personinntekt, personal income, is gross pay with nothing deducted at all. It is the base for trinnskatt and for the 7.6% trygdeavgift.
Worked example at NOK 700,000
| Step | Amount |
|---|---|
| Gross pay (personinntekt) | NOK 700,000 |
| Less minstefradrag | NOK 95,700 |
| Less personfradrag | NOK 114,540 |
| Alminnelig inntekt | NOK 489,760 |
The 22% is charged on NOK 489,760. Trinnskatt and national insurance are charged on the full NOK 700,000. The deductions shrank one base by more than NOK 210,240 and the other by nothing.
What this means for deductions
A Norwegian deduction is worth 22% of itself, full stop. Union fees, commuting costs, BSU savings and the rest all reduce ordinary income only. If you are used to systems where a deduction saves you tax at your marginal rate, Norwegian deductions will feel weak, because your marginal rate includes trinnskatt and national insurance that the deduction never touches.
And for the marginal rate
The same split explains why the Norwegian marginal rate climbs the way it does. At the top it is 22% plus 17.8% trinnskatt plus 7.6% national insurance, about 47.4%, even though no single published rate is anywhere near that. See the trinnskatt guide for the full bracket table.
The Norway salary calculator shows both bases in its breakdown, and the methodology page documents the sources.