🚗 RSK 4.03 Guide

Vehicle Expense Deductions in Iceland — RSK 4.03 Guide (2026)

Iceland uses an annual system: business mileage % × total car costs. Couriers and construction contractors can save 300,000–700,000 ISK per year.

TL;DR

You cannot deduct fuel or car maintenance monthly. Instead, Iceland uses an annual system: track your total mileage vs. business mileage, then deduct that percentage of all car costs via RSK 4.03. A courier driving 60% for work can save 300,000–700,000 ISK per year. FreelancePay Pro tracks this automatically.

1. The Key Rule: No Monthly Fuel Deductions

Unlike many countries, Iceland does NOT allow direct monthly deduction of fuel or maintenance. Instead, an annual calculation via RSK 4.03 — filed with your tax return (skattframtal) — is used.

The formula:

Business km ÷ Total km = % → × Total car costs = Deduction

2. What Counts as Business Mileage?

Counts as business mileage

  • Driving to/from clients
  • Delivery routes (Wolt, couriers)
  • Driving to job sites
  • Business-related errands

Does NOT count

  • Commuting to a regular workplace
  • Personal errands
  • Leisure trips
  • Unverifiable trips

Must be provable: mileage log (akstursdagbók) with date, destination, km, and purpose.

3. How to Fill Out RSK 4.03 — Step by Step

1

Section A: Vehicle details

Registration number, purchase price, year of purchase

2

Section B: Total km driven in the year

Odometer reading at year start vs. year end

3

Section C: Business km driven

From your mileage log

4

Section D: Business percentage

C ÷ B (e.g. 18,000 ÷ 25,000 = 72%)

5

Section E: Deductible costs

Insurance, depreciation (set by tax authorities), maintenance & repairs, fuel, parking & tolls

6

Section F: Your deduction

E × D (business %)

4. Example: Wolt Courier

Total km/year25.000 km
Business km18.000 km (72%)
Total car costs900.000 kr
Deduction (72%)648.000 kr
Tax saving (31.49%)~204.000 kr

17.000 kr

back in your pocket / month

(204,000 ISK ÷ 12 months)

5. Example: Construction Contractor

Total km/year30.000 km
Business km22.000 km (73%)
Total car costs (larger vehicle)1.400.000 kr
Deduction (73%)1.022.000 kr
Tax saving~322.000 kr/ár

6. How to Keep a Mileage Log

  • Digital apps are fine — FreelancePay Pro has built-in tracking
  • Minimum required: date, start/end location, km, business purpose
  • Take odometer photos at year start and end
  • Tax authorities can audit — incomplete logs = denied deduction

FreelancePay Pro Tracks Vehicle Expenses Automatically

Mileage log, annual summary, and RSK 4.03 calculation — all in one place. No spreadsheets, no mistakes.

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