some taxpayers don't know that every amount they enter can be rounded to whole $s. 50 or more up to the next whole dollar. less than $ .50 cents. every CPA firm that I ever worked for only uses whole $s except in the rare case where the return requires the use of cents. there are good reasons. many returns are billed based on time spent + computer costs. entering cents ups the time without significantly affecting the taxes due. others are billed a flat fee which means the firm nets less when it has to pay employees or independent contractors by the time spent.
the IRS would be stupid to go after $1.25. it does cost them money to send out the notice (paper and postage) then they have to open the reply and separate the notice from the check (manual labor) and see if they agree. then the check goes one place to be endorsed and deposited while the notice goes somewhere else to be entered in its computer system that payment has been made. (or some similar process)
yes the USPS does bill the IRS for poasyage. so by the time the IRS gets through with that $1.25 notice they've probably lost $1.25
