Death and taxes is a common reference to the famous quotation:
Our new Constitution is now established, and has an appearance that promises permanency; but in this world nothing can be said to be certain, except death and taxes.— Benjamin Franklin, in a letter to Jean-Baptiste Leroy, 1789
However, Franklin’s letter is not the origin of the phrase, which appeared earlier in Daniel Defoe’s The Political History of the Devil.
Things as certain as death and taxes, can be more firmly believ’d.
And in The Cobbler of Preston by Christopher Bullock (1716)
’Tis impossible to be sure of any thing but Death and Taxes,