A1 (formerly E101) is a certificate which documents that the employee is covered by social security in their home country during the employment period in Norway.
Without the certificate. The employer must pay employer’s contribution (Arbeidsgiveravgift) in Norway (up to 14,1%) and the employee must pay a social security contribution of 8,2% in order to be covered by social security in Norway. This is not optional.
Upon issuance of the A1 certificate it is automatically sent to the Norwegian authorities. Our experience is that this process often has some hiccups.
Therefore, it is important to get certificate A1 in place at the earliest convenient, so that it can be presented as documentation to relevant authorities – for example, the Central Tax Office for Foreign Affairs and Tax Collector Abroad.