A Newcastle woman has been asked to "show cause" as to why she should keep her personalised number plates, bearing her nickname Kiki, which means genitals in a Filipino language.

Kristen Perry is so attached to her nickname Kiki she has number plates on her car bearing that name.

But the word doesn't sit well with the Roads and Traffic Authority which says it is considered offensive in the Filipino language, Tagalog.

In that language the word is used to describe part of a woman's genitals and the RTA is now demanding Ms Perry show cause to keep the plates.

Ms Perry says she was shocked.

"I was taken aback," she said.

"At first I thought it was a joke, but then I realised it was actually quite serious and that my number plates would be taken off me if I didn't respond appropriately.

"Quite frankly it's a bit of a funny thing, but at the same time quite a bit scary that we've got people that can just report a number plate that seems seems quite inoffensive to 99 per cent of us out there, but one per cent have an issue with it."

Ms Perry says her nickname is linked to her Greek heritage and she is disturbed it could be considered offensive.