# Wrong tax assessment: amend it yourself or appeal?

Is your tax assessment wrong? Learn when to amend your tax return, when to appeal a decision, the relevant deadlines and which documents to prepare.

Canonical: https://samfunnprep.no/en/articles/feil-skatteoppgjor-endre-eller-klage
Language: en
Publisher: SamfunnPrep
Author: Hlib Suslov
Published: 2026-10-05T16:12:31.32+00:00
Modified: 2026-10-05T20:32:25.09697+00:00
AI use policy: https://samfunnprep.no/ai-policy.txt

## Key takeaways

- Choose the correct route Your own errors, an official decision and older income years may require different procedures.
- Check the year and deadline Your own amendment deadline runs from the filing deadline; the main appeal deadline is six weeks from the decision reaching you.
- Document and follow up Show the correct amount with relevant attachments, keep the submission receipt and pay ordinary outstanding tax by the deadline.

An error in your tax assessment often means you should correct the tax return and submit it again. If Skatteetaten decided the issue in a formal decision, you may need to appeal instead. Find the correct income year and route before submitting. Ordinary outstanding tax must be paid by the deadline while the case is processed.

## First establish what is wrong

Compare your tax assessment with the tax return and documents for the same income year. An unexpected amount does not necessarily mean Skatteetaten made a mistake.

The **tax return** contains information including income, debts and deductions. The **tax assessment** shows the calculated tax and whether you must pay or receive a refund. The **tax deduction card** determines how much your employer deducts during the year. The three documents serve different purposes.

Check the year at the top. A tax assessment received in one year normally concerns income from the previous year. Use the annual statement and salary information for that year, not just the latest payslip.

SamfunnPrep's [guide to the tax return](https://samfunnprep.no/en/articles/skattemelding-norge) explains the information to check. This guide helps you choose a route after identifying a specific error.

## When can you amend the tax return yourself?

In most cases, correct inaccurate or missing information in your tax return and submit it again. Receiving a tax assessment does not automatically remove this option.

Skatteetaten explains the choice between your own amendment, a request and an appeal on its [page about tax assessment errors](https://www.skatteetaten.no/person/skatt/skatteoppgjor/klage-pa-skatteoppgjoret/). The guidance was checked on 4 October 2026.

The main deadline for amending your own return is **three years after the filing deadline**. Skatteetaten's [handbook on the amendment deadline](https://www.skatteetaten.no/nn/rettskjelder/type/handboker/skatteforvaltningshandboken/gjeldende/kapittel-9-fastsetting/ID-9-5.001/ID-9-5.011/) shows this rule. Count from the relevant filing deadline, not the day your assessment happened to arrive.

You cannot freely use your own amendment for an item Skatteetaten has already determined in a decision or which is covered by a notified audit issue. Follow the guidance and letter for that item. Other information may have a different route.

| Situation | What do you investigate first? |
| --- | --- |
| You forgot information or entered it incorrectly | The possibility of amending and resubmitting the tax return |
| Skatteetaten decided the relevant item in a decision | The appeal route and deadline in the decision |
| The deadline for your own amendment has passed | A request to Skatteetaten for an amendment |
| Your employer reported incorrect tax deductions | Correction by the employer and Skatteetaten's specific guidance |

## When must you appeal a decision?

If you received a decision resolving the issue you disagree about, read its appeal information. Do not rely solely on an ordinary amendment to protest the decision.

A **decision** is an official determination by the authority. For example, it can reject a deduction you entered. The tax assessment and a separate decision letter can be different documents, so review the messages you received.

The main deadline under the Tax Administration Act is **six weeks from when notification of the decision reached you**. Skatteetaten's [guidance on the appeal deadline](https://www.skatteetaten.no/rettskilder/type/handboker/skatteforvaltningshandboken/gjeldende/kapittel-13-klage/ID-13-4.001/ID-13-4.003/) explains the rule.

Do not use a general three-week deadline from other public-service cases. Read the specific appeal instructions and contact Skatteetaten promptly if you are unsure when the deadline started or where to send the appeal.

SamfunnPrep's [guide to appealing public decisions](https://samfunnprep.no/en/articles/klage-pa-offentlige-vedtak-norge) explains how to structure a reasoned appeal letter. You must still check the tax deadline separately.

## What do you do about older income years?

When the deadline to amend the return yourself has passed, you can ask Skatteetaten to consider an amendment. Such a request is not an automatic approval.

Use Skatteetaten's guidance for the relevant year. Explain which information you want amended, why it is wrong, when you discovered it and what the documents show.

Do not choose the newest income year simply because it is easier to open in the system. Interest expenses or income must be assessed in the correct year. The wrong year can create another problem.

If you also have a decision with an appeal deadline, clarify the appeal route before sending an ordinary request. Do not assume a different type of enquiry protects the appeal deadline.

## How to document an error

A good explanation identifies the incorrect information, the correct information and the document supporting the change. You do not need to send every financial document you own.

Make a short overview showing:

- The income year concerned.
- The information or amount you believe is wrong.
- The amount you believe is correct.
- Why the amendment should be made.
- An annual statement, agreement or other relevant documentation.
- A reference to the decision if you are appealing.

Use clear filenames and mark relevant lines if the document is long. Do not hide parts Skatteetaten needs to understand the context. Submit through the secure channel indicated by the service or decision.

If your employer reported incorrect advance tax deductions, Skatteetaten says you should first ask the employer to correct them. It may therefore be necessary to correct information at its reporting source rather than only writing an appeal.

## An example: interest expense or a rejected deduction

The same wish for lower tax can require two different procedures. This example is hypothetical; it does not determine whether you are actually entitled to a deduction.

You find an interest expense in the bank's annual statement that is missing from your tax return. If the conditions and deadline for your own amendment are met, investigate how to enter the information and submit the return again.

In another situation, Skatteetaten has already sent a decision rejecting the same expense as a deduction. Then explain why the decision is wrong and follow the appeal instructions. Entering the amount again does not replace an appeal.

Write precisely: “The case concerns interest expenses for income year [year]. The attached annual statement shows [amount]. I request [specific amendment] because [explanation].” For an appeal, also identify the decision you are appealing.

## Must you pay while the case is processed?

Ordinary outstanding tax must be paid by the payment deadline even if you amend the return or appeal. Submission does not, by itself, stop the payment demand.

Skatteetaten expressly states this on its [page about outstanding tax](https://www.skatteetaten.no/person/skatt/skatteoppgjor/restskatt/). Check the amount, due date and payment information on the demand you received.

If payment is difficult, contact Skatteetaten about solutions that may be considered. Do not wait silently for an appeal reply and assume the deadline has moved. Keep the receipt for your payment too.

This guidance concerns ordinary outstanding tax. A decision imposing additional tax penalties may have separate rules and requires specific guidance.

## After submission: check the receipt and new assessment

Check that the amendment was actually submitted, rather than merely saved. Keep the submission receipt and monitor further messages from Skatteetaten.

For your own amendment, [Skatteetaten's tax return page](https://www.skatteetaten.no/person/skatt/skattemelding/skattemelding-for-person/) shows how to amend and submit. An appeal or request may receive a separate response before any new assessment.

Read the new response before closing the matter. Check whether the authority addressed the exact item you raised and whether the amount or payment demand changed.

Use [SamfunnPrep's first-week checklist](https://samfunnprep.no/en/verktoy/forste-uke) to organise logins and contact with authorities. Keep the tax case in a separate folder with the year, documents and all receipts.

## FAQ

### Can I amend my tax return after the tax assessment?

As a main rule, you can correct your own information within three years after the filing deadline. Items determined by Skatteetaten or taken up for audit may require another route.

### How long is the deadline for appealing a tax decision?

The main deadline is six weeks from when notification of the decision reached you. Read the appeal instructions in your decision and clarify uncertainties promptly.

### What do I do when my own amendment deadline has passed?

You can request an amendment from Skatteetaten. Explain the year, error and documents. The authority must assess the case; amendment is not automatic.

### Must I pay outstanding tax while appealing?

Yes, ordinary outstanding tax must be paid by the deadline even when you amend or appeal. Contact Skatteetaten if you need payment guidance.

## Sources

- [Klage på skatteoppgjøret](https://www.skatteetaten.no/person/skatt/skatteoppgjor/klage-pa-skatteoppgjoret/)
- [Skattemeldingen – se, endre eller levere](https://www.skatteetaten.no/person/skatt/skattemelding/skattemelding-for-person/)
- [Skatteforvaltningshåndboken: § 13-4 første ledd](https://www.skatteetaten.no/rettskilder/type/handboker/skatteforvaltningshandboken/gjeldende/kapittel-13-klage/ID-13-4.001/ID-13-4.003/)
- [Restskatt](https://www.skatteetaten.no/person/skatt/skatteoppgjor/restskatt/)
- [Skatteforvaltningshåndboken: § 9-4 annet ledd](https://www.skatteetaten.no/nn/rettskjelder/type/handboker/skatteforvaltningshandboken/gjeldende/kapittel-9-fastsetting/ID-9-5.001/ID-9-5.011/)

Citation: Hlib Suslov, "Wrong tax assessment: amend it yourself or appeal?", SamfunnPrep, 2026-10-05T16:12:31.32+00:00, https://samfunnprep.no/en/articles/feil-skatteoppgjor-endre-eller-klage