Number plate failed MOT

£20 is a bit steep for a single number plate. The advice above is correct.

Plate must be able to be read clearly at a distance of 20m

The failure for delaminated plates does exist, but surely for a plate that is delaminated to the extent that it has become difficult to read? After all there is a failure for deteriorated, but I wouldn't use it just because of a scratch. Can you post a photo of the plate alggomas? That would give us a chance to see how much delamination has occurred.

Exactly so, the advisory is delaminated but unlikely to be misread. So no need for a fail if the gent can wash the vehicle and not even notice it was damaged at all.

I use this rfr regularly on a p+a. Has to be bad though, in fact I think I have not actually failed one.