D-number and fødselsnummer

Almost everything you need to sort out in Norway requires one of these two numbers, and they are not the same thing.

The difference

D-number is a temporary identity number. You get one if you're staying in Norway for a shorter period, or if you need to deal with Norwegian authorities without being registered as resident.

Fødselsnummer is a permanent number, and you get it when you're registered as resident in the National Registry (Folkeregisteret).

Why it matters

Because many services treat them differently. Some things you can do with a D-number, others require a fødselsnummer. Banks, BankID and certain public services are the most common places people run into this limit.

If you have a D-number and plan to stay

Then registering as resident in the National Registry is the next step, and the fødselsnummer follows from that. It's not something you apply for separately.

What this has to do with the test

Nothing directly. But it's in the syllabus: how public authorities work and what rights and duties you have as a newcomer is a learning objective in its own right.