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Different rules apply regarding eligibility for Norwegian citizenship for people with residence permits in Norway, people with residence cards for family members of EU/EEA nationals, Nordic nationals and people who have previously been Norwegian citizens.
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The applicant is the person who wishes to become a Norwegian citizen.
If you are a citizen of two or more countries, and one of them is an EU/EEA country, please choose the EU/EEA country.
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There is no separate application form for dual citizenship. When you apply for Norwegian citizenship, you do not need to notify UDI that you want to keep your other citizenship. You can read more about dual citizenship here.