Obligation to pay national insurance contributions
Any person working in Norway must pay a national insurance contribution of 7.8 percent of his/her pay and other compensation for work and assignments performed in or out of service. The national insurance contribution is paid together with the tax.
If you submit form E101 from the national insurance service of your home country, you do not need to pay a national insurance contribution to Norway.
Obligation to pay the employer's contribution
Your employer must pay the employer's contribution to the national insurance scheme of your pay and other remuneration for work and assignments performed in or out of service. In Norway the obligation to pay employer's contributions is linked to the employer's obligation to submit a report on pay and other remuneration for work to the tax authorities.
Also foreign employers must pay the Norwegian employer's contribution on pay and remuneration for work performed in Norway and on the Norwegian continental shelf. This applies regardless of whether the foreign employer is tax liable to Norway because he carries out business activities in Norway through a permanent establishment here, and regardless of whether the employee is liable to tax in Norway.
If the employee submits the E101 form from the national insurance authorities in his/her home country, the employer does not need to pay the Norwegian employer's contribution.