Generally, you can be 3 months away without affecting your application for Icelandic citizenship. However, for a longer time you must look at the exemptions from continuous residence.

• To maintain a continuous residence, you must not have stayed abroad for longer than 90 days in total in each 12-month period

• If you stay abroad for longer than 90 consecutive days in a 12-month period, that stay does not count towards the qualifying residence period that applies to you.

• Please note that an applicant must satisfy the seven-year residence qualification before applying for Icelandic citizenship, even though an exemption is granted from the condition on continuous residence.

Instead of the stay abroad being deducted from the period of stay in Iceland, it is stopped if the exemption is approved. Then you still must have stayed in Iceland for a total of seven years.