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You need valid insurance from the moment you take over the vehicle, even if it's a Saturday evening. Insurance can be taken out online around the clock. Waiting until Monday earns you a fee for the whole weekend.
The myth that you can "wait until Monday" to insure a car if you buy it over a weekend when customer support is closed is one of the most expensive misunderstandings around buying a car. The law doesn't take weekends off.
You don't need to talk to anyone
Most insurance companies and comparison sites have automated systems that let you take out a policy in a couple of minutes on your phone, in the middle of the night. You don't need to wait for the registration certificate. An insurer offering motor insurance generally can't refuse to sell it to you.
It doesn't have to be the "right" company right away, either. Take out a policy with whichever company you can reach on the spot to make the purchase legal, then compare and switch later at your leisure. Switching companies afterwards is free.
If the systems are down
Standing at the seller's on a Sunday evening with the insurer's website not working? Send a written request through the company's own contact channel or email. Include the registration number, your name, and the exact date and time you want cover to start. Share your personal ID number by phone or through the company's login instead of in a plain email. The written request gives you a timestamp if there's ever a dispute about the start date.
Sources: Swedish Motor Insurers' Committee, about vehicle insurance. Traffic Damage Act (1975:1410) §5. Last checked: 2026-09-21.