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Filing a Tax Return in Iceland (2026 Legal Guide) — Rules & Requirements

Source: Lög um tekjuskatt (nr. 90/2003)

About this article

Sourced from Icelandic Acts of the Althingi, statutory instruments, and official guidance. Written in plain language for general understanding — this is educational content, not legal advice. Our editorial standards

Icelandic National Law

What is this right?

All taxpayers in Iceland must file an annual tax return:

  • Filing deadline: 13 March 2026 for the 2025 income year (individuals filing electronically; Skatturinn does not grant individuals extensions). Accountants/bookkeepers filing on a client's behalf have until 15 April 2026.
  • Pre-filled return: Skatturinn offers a pre-filled return with information on wages, real estate, vehicles, bank accounts and debts. You confirm or correct it.
  • Penalty for late filing: Up to 25% surcharge on the estimated additional tax when a return is not filed.
  • Assessment timeline: The final assessment is generally completed by 31 May of the assessment year.
  • Payment of the difference: Additional tax is spread over 7 instalments. Overpayments are refunded.
  • Right to correct: You can file a corrected return to fix errors or omitted information.

When does it apply?

  • You have legal domicile in Iceland and received taxable income in the past year.
  • Even if the return is pre-filled, you are responsible for its accuracy.

What to do if you missed the tax-return deadline or made an error on your return in Iceland

  1. Log in to skattur.is with electronic ID (electronic ID in your phone or on an e-ID card) or Íslykill (a web key issued by Registers Iceland).
  2. Review the pre-filled return carefully — check the wage information, real estate, vehicles, bank accounts and debts that Skatturinn has imported. Look for omitted income, incorrect deductions or outdated information.
  3. Add deductions and corrections — interest expenses on housing, mortgages, gifts, professional-association fees, foreign income and items not filled in automatically.
  4. File by 13 March 2026 for the 2025 income year (Skatturinn does not grant individuals extensions). Accountants/bookkeepers filing on a client's behalf have until 15 April 2026. If you discover an error after filing, file a corrected return as soon as possible.

What should you NOT do?

  • Don't let the March deadline lapse — the 25% surcharge on the estimated tax is significant.
  • Don't assume the pre-filled return is always correct — you are legally responsible for its accuracy.
  • Don't throw away records — keep all supporting documents for at least 6 years.

Common Questions

When is the Icelandic tax-return deadline?

13 March 2026 for the 2025 income year (individuals filing electronically). Skatturinn does not grant individuals extensions. Accountants and bookkeepers filing on behalf of clients have until 15 April 2026. The final tax assessment is generally completed by 31 May of the assessment year. Additional tax is spread over 7 instalments, while overpayments are refunded.

Do I have to fill in the Icelandic tax return from scratch?

No. Skatturinn offers a pre-filled return with information on wages, real estate, vehicles, bank accounts and debts. You confirm or correct it through Skatturinn's service portal (RSK). Although it is pre-filled, you are legally responsible for its accuracy — review it carefully for missing income, incorrect deductions or outdated information.

What is the penalty for filing a tax return late in Iceland?

A surcharge of up to 25% on the estimated additional tax applies when a return is not filed on time. You can file a corrected return to fix errors or omitted information after filing. Keep all supporting documents for at least 6 years. File electronically through Skatturinn's service portal as soon as possible if you miss the March deadline.

What is the filing a tax return right in Iceland?

All taxpayers in Iceland must file an annual tax return:Filing deadline: 13 March 2026 for the 2025 income year (individuals filing electronically; Skatturinn does not grant individuals extensions). Accountants/bookkeepers filing on a client's behalf have until 15 April 2026.Pre-filled return: Skatturinn offers a pre-filled return with information on wages, real estate, vehicles, bank accounts and debts. You confirm or correct it.Penalty for late filing: Up to 25% surcharge on the estimated additional tax when a return is not filed.Assessment timeline: The final assessment is generally...

When does it applyfiling a tax return?

You have legal domicile in Iceland and received taxable income in the past year.Even if the return is pre-filled, you are responsible for its accuracy.

What should I do if I missed the Icelandic tax-return deadline or need to correct an error on my return?

Log in to skattur.is with electronic ID (electronic ID in your phone or on an e-ID card) or Íslykill (a web key issued by Registers Iceland).Review the pre-filled return carefully — check the wage information, real estate, vehicles, bank accounts and debts that Skatturinn has imported. Look for omitted income, incorrect deductions or outdated information.Add deductions and corrections — interest expenses on housing, mortgages, gifts, professional-association fees, foreign income and items not filled in automatically.File by 13 March 2026 for the 2025 income year (Skatturinn does not grant...

What should you NOT dofiling a tax return?

Don't let the March deadline lapse — the 25% surcharge on the estimated tax is significant.Don't assume the pre-filled return is always correct — you are legally responsible for its accuracy.Don't throw away records — keep all supporting documents for at least 6 years.

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