(as) certain as death and taxes

(as) certain as death and taxes

Certain to happen; inevitable and unavoidable. A variation of the proverbial phrase, "Nothing is certain but death and taxes." They just aren't right for each other; they're certain as death and taxes to break up eventually. The two brothers will be forever at each other's throats, as certain as death and taxes.
See also: and, certain, death, taxes
Farlex Dictionary of Idioms.

death and taxes, certain as

Also, sure as death and taxes. Bound to occur, inevitable, as in His business is going to fail, certain as death and taxes. This phrase was invented by Benjamin Franklin in a letter (1789) and has been repeated ever since, the government's recurring need for revenue probably assuring its continued popularity.
See also: and, certain, death
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • (as) sure as death and taxes
  • death and taxes, certain as
  • taxes
  • death and taxes
  • certain
  • under certain conditions
  • treat (someone or something) like (someone or something else)
  • treat like
  • under certain circumstances
  • be a dead cert