First, check the register no longer says you
Everything below rests on one fact, and the fact is a line in the RDW register. The RDW tells sellers to keep the car until the vrijwaringsbewijs is in their hands, so if you did that, the proof is already in your folder. If the car drove off before the paperwork was done, find out today where things stand.
Mijn RDW with DigiD will tell you, and so will the Kentekencheck if you type the plate in. What you want to see is the car absent. A car still listed under your name is still your tax, your insurance duty and your fine. Chase the buyer, and take it to the RDW if chasing leads nowhere. Our guide to the vrijwaringsbewijs describes the document in full.
The road tax takes care of itself
This is the one item on the list where doing nothing is the correct move. The RDW reports the change of keeper to the Belastingdienst, and tax covering the period after the car left you is paid back without a request, whether you pay by direct debit or not. Small sums are kept back. Our road tax page has the detail.
Two cases break that pattern. A bill for the weeks before the sale is yours, and the Belastingdienst says so plainly. And a car under the oldtimer transitional scheme produces no refund at all, so there is nothing to wait for.
Nobody ends your insurance except you
The RDW has no connection to your policy. Selling the car does not touch it, the cover simply continues, and so does the premium. WA cover is compulsory while a car is in your name, and the RDW does check registered cars against insurance records, so letting a policy lapse early is a problem of its own. After the transfer the buyer needs cover from day one, which is their concern and no longer yours.
Phone the insurer with the vrijwaringsbewijs in front of you and read out the date and the time printed on it. End dates are a matter of policy terms, and terms differ between insurers, so ask for the exact date in writing. If the proof has gone missing, the RDW publishes a free overview of the vehicles that have been in your name, and most insurers take that.
A suspension lapses, a parking permit does not
If the car was suspended when you sold it, there is nothing to cancel. Registering a new keeper ends the suspension automatically. The parking permit is the opposite case. It belongs to the gemeente that issued it, every gemeente writes its own rules, and none of them watch the RDW register on your behalf. Ring the one that gave you the permit and ask whether it has to be cancelled and whether any of the fee comes back.
Treat anything else local in the same way, a permit for an environmental zone being the usual example. The RDW and the Belastingdienst have no hand in those, so if you do not raise it, nobody will.
The document that answers a letter six months on
A vrijwaringsbewijs carries a date and a time, and that precision is the whole reason to keep it. A fine or a bill for a moment after that time is answerable with one attachment. A fine timed before it stays yours. Compare the two timestamps before writing a single line of objection.
Keep the proof, the sales contract if there was one, and the messages you exchanged with the buyer. The RDW names no retention period. A workable rule: hold them for as long as a letter about that car could still realistically land on your mat.
If the country is next on the list after the car
A sale is one line in a longer list for anyone moving abroad, and the lines have an order to them. DigiD, the population register and the insurer each depend on the others being done at the right time. That order is set out in our guide to the last weeks here, and our transfer guide handles the sale on its own.