Anyone who has tampered or altered their car number plates are being warned they could be stopped and fined at any time.
Police in Gloucester say they are coming across more vehicles with the numbers and letters altered than ever before.
A spokesman for the Gloucestershire Constabulary, said the offenders usually change numbers and letters around to form names and other types of words.
He said it is an offence under the Road Vehicles Regulations Act to change the characters on number plates in any way.
Offenders can be fined £60 for this offence.
There are set rules supplied by DVLA for how number plates should be made up, all number plate suppliers should therefore stick to these rules.
Police Community Support Officer Steve Harris said: "I believe we've issued around 60 fines in the last six months, which is not a good sign.
"I'm not sure why but a few motorists believe they have the right to alter their registration plates just because it suits them. In fact, they could not be more wrong."
In addition to the fine, the owner will also receive a letter in the post from DVLA ordering them to change their number plate back to how it should look.