postcode vs postal code

postcode and postal code both are nouns.

Word	Noun	Adjective	Verb	Adverb
postcode	Yes	No	No	No
postal code	Yes	No	No	No

As nouns, postcode and postal code are synonyms defined as:

postcode and postal code: a code of letters and digits added to a postal address to aid in the sorting of mail

Other synonyms of postcode include ZIP, ZIP code.

postcode (noun)	postal code (noun)
a code of letters and digits added to a postal address to aid in the sorting of mail	a code of letters and digits added to a postal address to aid in the sorting of mail