What is a mileage log? A plain explanation for 2026
A mileage log is a record of every trip you take by car. Here is exactly what it must contain, who needs one, and why.
A mileage log is a continuous record of every trip you take by car. For each trip you note the date, start and stop time, odometer reading at start and stop, start and end of the route, the purpose of the trip and the driver. That is the information needed for the Swedish Tax Agency (Skatteverket) or an auditor to decide whether a trip was business or private.
Who needs one
Three groups must keep a log in practice. The first is employees with a company car who want to avoid full benefit taxation. The second is business owners who want to deduct car costs in the business. The third is owners of closely-held companies who must separate private and business driving to avoid unwanted tax consequences.
There is a fourth group that often forgets they need a log: consultants and self-employed people who use a private car for business and want to claim per-kilometer reimbursement. Without a log, no reimbursement that holds up to audit.
What every line must contain
Skatteverket is very clear about what each line must show:
- Date and time for departure and arrival
- Odometer reading at start and stop
- Start and end address or location
- Purpose of the trip if it is for business
- Driver’s name
If any of the five fields are missing the line is not complete. A complete log is one where no line has gaps.
Why the “purpose” field matters most
Odometer, time and location can be reconstructed to some extent. Purpose cannot. Was the trip to a client? Which client? Was it a meeting, a delivery, training? That information lives only in your head, and every passing day makes it fuzzier. That is why most mileage logs fail on the purpose field during an audit.
Manual or automatic
A mileage log can be kept manually with paper, a spreadsheet or an app. It can also be kept automatically if the car reports the trip data. For Tesla cars the latter is standard, because the car already knows everything except purpose and driver. We have written more in Automatic vs manual mileage log.
Why it is worth the trouble
Without a log, a company car is automatically taxed at the full benefit value, even if you barely drive privately. The default benefit amount is often tens of thousands of SEK in tax per year. For self-employed people it means the car costs cannot be deducted in the business. It is more expensive not to keep a log than to keep one.
What MPH DriveLog does
DriveLog pulls trip data directly from your Tesla, classifies trips against your rules, and builds a log that meets Skatteverket’s requirements. You review trips whenever you want and export PDF or CSV when it is time. It is no revolution. It is just automation of something that would otherwise take ten minutes a day by hand.
“Is a spreadsheet log enough?”
Yes, if it is complete and kept continuously. The continuous part is the hard one to maintain over time.
Want to go deeper? See Mileage log according to the Swedish Tax Agency. Rules and requirements and Common mistakes in mileage logs as natural next steps.