British pound vs British pound sterling

British pound and British pound sterling both are nouns.

Word	Noun	Adjective	Verb	Adverb
British pound	Yes	No	No	No
British pound sterling	Yes	No	No	No

As nouns, British pound and British pound sterling are synonyms defined as:

British pound and British pound sterling: the basic unit of money in Great Britain and Northern Ireland; equal to 100 pence

Other synonyms of British pound include pound, pound sterling, quid.

British pound (noun)	British pound sterling (noun)
the basic unit of money in Great Britain and Northern Ireland; equal to 100 pence	the basic unit of money in Great Britain and Northern Ireland; equal to 100 pence