Author: Ragnhild Myren Stephansen
The deadline for submitting the Norwegian tax return for the 2025 income year was 30. April 2026. Even so, many taxpayers only discover afterwards that something is missing — for example deductions, foreign income, or an incorrect assessment of tax residency.
Fortunately, this does not mean it is too late to take action. In many cases, errors can still be corrected after the filing deadline, helping ensure that you do not pay more tax than necessary.
You can amend your tax return yourself – up to three years back
If you discover errors, missing information, or receive new or delayed documentation, you can amend your Norwegian tax return digitally through the Norwegian Tax Administration’s portal. This can be done either by yourself or through an authorized representative.
This applies even if the tax return has already been processed and a tax assessment has been issued.
As a general rule, self‑amendments can be made for up to three years after the filing deadline.
In practical terms, this means:
- The 2025 tax return can be amended until 30. April 2029
- The 2024 tax return can be amended until 30. April 2028
- The 2023 tax return can be amended until 30. April 2027
If the amendment affects your tax calculation, the Tax Administration will issue an updated tax assessment. If the change does not affect the tax calculation, a new assessment will normally not be issued.
When the deadline for self‑amendment has passed
If the deadline for self‑amendment has expired, it may still be possible in certain cases to have the tax return corrected if the tax assessment is incorrect. In such situations, you must submit a formal request for amendment (appeal) to the Norwegian Tax Administration.
As a general rule, a 5‑year deadline applies, calculated from the end of the relevant income year, for requesting changes to an incorrect tax assessment. After this period, it will normally no longer be possible to have the case reopened for amendment.
This may be particularly relevant for the 2021 and 2022 income years, where it is no longer possible to make changes directly in the tax return yourself.
When assessing whether a case will be reopened, the Tax Administration typically considers factors such as:
- the taxpayer’s individual circumstances
- how much time has passed
- the importance of the matter
- whether the case is sufficiently documented
Each case is assessed individually.
When is it especially important to review and make changes?
It is advisable to review your tax return carefully even after the deadline.
Amendments may be particularly relevant if:
- deductions were forgotten or reported incorrectly in example standard deduction, interest on loan, seafarers’ allowance
- foreign income or assets were not correctly disclosed
- your tax residency status was assessed incorrectly
- you were tax resident outside Norway and received salary that should not be taxable in Norway, for example because you were on sick leave abroad or stayed outside Norway due to training or courses
- supporting documentation became available after the return was filed
Such issues are more common than many taxpayers realise and may lead to paying too much tax if left uncorrected. Even after the filing deadline has passed, reviewing and correcting your tax position can therefore be both possible and financially worthwhile.
Do you need assistance?
It is always wise to review your tax return thoroughly — even after the deadline has passed. Many taxpayers only later discover that deductions are missing or that information has not been handled correctly.
By making the necessary amendments, you can ensure that your tax position is accurate and avoid paying more tax than required.
Nomadexus regularly assists clients with reviewing and correcting Norwegian tax returns, including after the filing deadline has passed.
Can I amend Norwegian tax return after the deadline? Yes, you can amend Norwegian tax return for up to three years after the filing deadline.
You are welcome to contact us or book a consultation through our website.