numberplate vs license plate

numberplate and license plate both are nouns.

Word	Noun	Adjective	Verb	Adverb
numberplate	Yes	No	No	No
license plate	Yes	No	No	No

As nouns, numberplate and license plate are synonyms defined as:

numberplate and license plate: a plate mounted on the front and back of car and bearing the car's registration number

numberplate (noun)	license plate (noun)
a plate mounted on the front and back of car and bearing the car's registration number	a plate mounted on the front and back of car and bearing the car's registration number