totally fine to bunch donations in one year to try and itemize.  nothing wrong with it so there is no IRS ruling on it.   i think it is less of a thing these days with the standard deduction being so large

how many years are allowed in a single year bunch donation deduction?

@abctax55 So based on that example the "max" amount of years you can "bunch" is 2. My google searches yielded plenty of posts about bunching 3-5 years... which clearly would not fit that "bunch" description you outlined.

Ive never heard of bunching over multiple years.   Got an IRS link to share?

Bob's Barber shop's bulletin board. 😁

It's often (or, was in prior years/decades) done to get over the standard deduction amount - more so with property taxes.  In Ca, property taxes are due twice a year,  BUT you can pay three installments in one year (then only one in the following year).

It could also be done with State estimated tax payments...pay the 1.15 one by 12.31 to move the deduction into the year wanted.  

Year one - over the standard deduction so itemize.  Following year, standard deduction.

The large standard deduction, plus SALT eliminated this strategy.

It's not an IRS *code* other than the concept of cash basis.  You deduct 'it' when you pay (or donate) it.