What does PRS mean on an MOT?

PRS stands for Pass after Rectification at Station. It shows up on an MOT record when a car initially failed its test, but the fault was fixed there and then, within an hour, at the same test centre, and the tester then re-checked it and passed it.

For the test centre's own record-keeping, a PRS still counts as an initial fail, even though the certificate itself is a genuine pass. What it means for you as a buyer: the car did have something wrong with it on the day, but it was fixed immediately rather than being sent away with the fault unresolved.

It's not something to be alarmed about on its own - lots of PRS faults are quick fixes like a bulb or a wiper blade. If you can see what the original fault was, for example on an MOT history check, it's worth a glance, since a genuinely minor fix is a different story to something more involved that just happened to be fixable within the hour.

Source: gov.uk: MOT testing guide, documentation