account book vs book of account

account book and book of account both are nouns.

Word	Noun	Adjective	Verb	Adverb
account book	Yes	No	No	No
book of account	Yes	No	No	No

As nouns, account book and book of account are synonyms defined as:

account book and book of account: a record in which commercial accounts are recorded

Other synonyms of account book include book, ledger, leger.

account book (noun)	book of account (noun)
a record in which commercial accounts are recorded	a record in which commercial accounts are recorded