annually vs p.a.

annually and p.a. both are adverbs.

Word	Noun	Adjective	Verb	Adverb
annually	No	No	No	Yes
p.a.	No	No	No	Yes

As adverbs, annually and p.a. are synonyms defined as:

annually and p.a.: by the year; every year (usually with reference to a sum of money paid or received)

Other synonyms of annually include each year, per annum, per year.

annually (adverb)	p.a. (adverb)
without missing a year	by the year; every year (usually with reference to a sum of money paid or received)
by the year; every year (usually with reference to a sum of money paid or received)