There are two ways to become a Norwegian citizen: by application or notification. Individuals eligible for citizenship by notification are those who are above 18 and have lived in Norway for seven years. Citizens of Denmark, Sweden or Finland may give notification to become a Norwegian citizen, as well. There is no fee associated with this kind of citizenship schema. To become a citizen by application, there are many more requirements. The fee to apply for Norwegian citizenship is NOK 2,500, according to the Norwegian Directorate of Immigration.
All applicants for Norwegian citizenship must be above the age of 12. This requirement does not apply to refugees and other stateless individuals, or to people applying concurrently with their parents or with a Norwegian parent.
Individuals applying for Norwegian citizenship must have lived in Norway for the at least seven of the previous 10 years on residence permits of at least one year durations. All potential citizens must meet the requirements for obtaining a permanent residence permit, which includes continuous three-year stay in Norway previous to being given a permanent residence permit. The three years preceding the permanent residence permit must be made up of residence permits of at least one year duration. The longest you can stay out of Norway is two months total in one calendar year to still be eligible for citizenship under the "seven years in a 10-year time period" requirement.
Individuals applying for citizenship must have completed 300 hours of study of the Norwegian language or documentation that sufficiently illustrates sufficient skills in Norwegian or Saami. In addition, individuals must clarify their identity by providing a passport from their country of origin. The passport must be valid during the entire immigration process. Finally, individuals convicted of criminal offenses or who have been forced to undergo psychiatric therapy or treatment may be rejected or placed on a probationary citizenship period in which there is a time frame before full citizenship is conveyed. The length of the probationary period depends on the seriousness of the criminal infraction.