Officially no but you wouldn't get pulled unless something else was wrong IE speeding or a light out, then you would just plead ignorant & say they were on the car when you bought it

...the reason they are not legal is because British Regs state the Reg plate has to be a specific Size & Font becuase some cannot be read as clearly from a distance IE speed camera's etc but these look fine IMO and I may get some myself. They are sold as 'show plates' becuase they are not road legal but you won't have to drive too far before you see someone else with a different style font reg plate, they seem really popular round here atm lot's of german style ones on M3's...