Taxes
Make year-end easier with records you can find.
- Updated
- Sources reviewed
- Tax year
- 2026
A self-employed person files the individual tax return with a business statement (RSK 4.11) showing business income, calculated remuneration, deductible expenses and profit. The return opens in March; filers with a business can request an extension. At assessment the year's withholding is credited against the final tax and the difference refunded or collected.
Key figures
- Form
- RSK 4.11 business statement
- with the individual return
- Opens
- March
- deadline announced by Skatturinn
- Vehicle costs
- RSK 4.03
- vehicle operating statement
- Assessment
- spring–summer
- withholding credited
Reviewing the year is simpler when invoices, receipts and payments are organised. Start with the records, then establish what needs to appear in your return.
The return and the supporting records
After the business year ends, the business results must be reported with the tax return. The relevant supporting forms depend on the business. A tax return, annual financial statements and a simple annual summary are different documents. Skatturinn: business tax returns.
Use the appropriate filing year and instructions. A return submitted in one year may concern income earned in the previous year. Check the current deadline with Skatturinn instead of relying on a date in an older article.
Gather these before starting
- The year’s invoices and credit notes.
- Receipts, expense explanations and records of business use.
- Payment records and outstanding invoices.
- Information about wages, withholding, pension and other relevant filings.
- Questions about entries that need individual review.
Work through one period at a time. List missing information and resolve it before finishing the review. If a bookkeeper is helping, provide a consistent set of records and explanations in one place.
What does Fustle provide?
An annual summary of information in the service is included and helps with preparation. It does not confirm that a tax return has been filed. Preparing and submitting an annual tax return is a separate service in development; its price has not been published. You remain responsible for making sure your return is submitted.
Quick answers
Is the annual summary enough on its own? That depends on your full financial position and business. Review it alongside the other records.
What happens after submission? Keep the confirmation and review the assessment when available. Skatturinn: understanding your assessment.
Sources checked 23 September 2026. General preparation guidance, not preparation of your individual return.
Frequently asked questions
Do I file a return even though I filed monthly returns all year?
Yes. Monthly returns are prepayments. The tax return shows the year's total income, expenses and profit and determines the final tax.
What is profit in a sole proprietorship?
Business income less calculated remuneration, payroll costs and deductible expenses. It is added to your income tax base and taxed in the brackets.
Can I carry a loss forward?
A sole proprietorship's operating loss can, subject to conditions, be carried forward against later profits. The rules are in the Income Tax Act; seek advice if the loss is significant.
Sources
- Skatturinn — framtalsskil rekstraraðilaskatturinn.is/atvinnurekstur/ad-hefja-rekstur/framtalsskil/
- Skatturinn — tax assessment (English)skatturinn.is/english/individuals/tax-return/tax-assessment
- RSK 4.03 — rekstraryfirlit fólksbifreiðar 2026 (PDF)skatturinn.is/media/rsk04/rsk_0403_2026.is.pdf
- Lög um tekjuskatt nr. 90/2003althingi.is/lagas/nuna/2003090.html
- Lög um tekjuskatt nr. 90/2003, 31. gr. (rekstrarkostnaður)althingi.is/lagas/nuna/2003090.html#G31
General information, not advice on your situation. Skatturinn and other authorities assess each case. Check the review date and sources before relying on a figure.
Related content
- TaxesTaxes and contributions for the self-employedWhich taxes and contributions does a contractor in Iceland pay in 2026? Income tax in three brackets, personal tax credit of 72,492 ISK, social security 6.35%, pension 15.5% and VAT. How they add up and when to file.
- Expenses and deductionsCapture the receipt while the purchase is still fresh.Capture receipts, record why a purchase relates to work and review AI-extracted details. Clear expense records make the next steps easier.
- Expenses and deductionsVehicle expenses start with how the vehicle is used.Separate business and personal vehicle use, collect receipts and prepare records for reviewing car expenses. Start with evidence before deductions.
- TaxesWithholding tax: monthly filing on your own salaryHow a self-employed person in Iceland files withholding tax on calculated remuneration: what the return contains, due date on the 1st and final due date on the 15th of the next month, surcharges, wage statements and how withholding is settled at assessment.
- Figures and datesTax calendar for the self-employed in IcelandEvery deadline the self-employed in Iceland need in 2026: withholding tax and social security by the 15th of each month, VAT every two months, pension contributions, wage statements and the annual tax return.
Where does Fustle fit in?
Record the work and create the invoice. The service you choose determines the support included.