Translation guide
A 'number plate' is the metal or plastic plate attached to a vehicle displaying its registration number. In Japanese, the most common term is ナンバープレート, a loanword from English. There are also native Japanese terms used in official or formal contexts.
number plate
The physical plate on a car, motorcycle, or other vehicle that shows its license number.
The most common and widely understood term in everyday conversation. It is a loanword from English 'number plate'.
That car's number plate is bent.
Short for ナンバープレート. Very common in casual speech. Can also refer to the number itself.
Write down the number plate.
Formal, official term used in legal documents and regulations. Literally 'vehicle number plate'.
It is mandatory to attach a number plate.