Sense with Cents

We have made this kind of call ourselves for about as long as Medlin has existed. Back in the floppy disk era, sending out a software update meant mailing a physical set of floppies to every affected customer. We kept a simple internal rule: small corrections rode along with the next regular update instead of triggering a special mailing of their own. Not to save on postage. A customer who opens an unexpected envelope assumes something serious is wrong, and explaining that the something was tiny does not reassure anyone. It just raises a question nobody needed to ask.

Downloads removed that decision entirely. There is no mailing to weigh anymore, no envelope, no threshold to clear — every correction goes out the moment it exists, folded into the normal flow of updates like everything else. I do not miss having to make that call.

But the underlying question behind it — how much is worth making noise about — never really disappears. It just shows up somewhere else. The place I see it most now is not our software at all. It is tax withholding, and who gets blamed when the numbers do not land exactly on zero.

Withholding was never trying to hit your number

Withholding tables exist to collect roughly enough tax across the year to keep most people close to square at filing time. Not to calculate anyone's exact final bill in advance. Close enough is not a side effect of the system. It is the design, and it has been the design for as long as there has been a withholding table. Sometimes that design produces a number that looks alarming on its face — zero federal withholding is the extreme version of that, and it is often exactly correct.

For a long stretch of years, roughly enough tended to run a bit high, and a lot of people got comfortable with a sizable refund every spring — their own money, coming back a year late, with the government paying no interest on the loan. Every so often the tables get pushed the other way on purpose instead. It happened in 1992, when the IRS printed its own warning directly inside that year's employer tax guide: the new tables would raise take-home pay right away, and some employees would owe money the following spring because of it. It happened again in 2018, when new tables went out with a public estimate that ninety percent of wage earners would see bigger paychecks immediately, while members of Congress asked the Government Accountability Office to check whether the tables were quietly built toward underwithholding. Different decades, same lever. Withholding is easy to move. Actual tax liability is hard to move. A bigger number on the paycheck reads as a win, no matter what happens the following April.

There is a target, and some people aim for it

For individuals, the IRS spells out exactly how close is close enough: pay in, through withholding and any estimated payments combined, at least the smaller of ninety percent of what you owe this year or one hundred percent of last year's bill — one hundred ten percent on the higher end. Hit that number and there is no underpayment penalty, even if you owe the rest at filing. That is not a loophole. It is the published rule.

Some people manage toward that number on purpose, on the theory that their own money is worth more in their pocket during the year than sitting at the IRS. Everyone else runs withholding like a Christmas savings club instead — overpay without much thought, then treat the spring “refund” like a windfall, rather than what it actually is: their own money, handed over early, at no interest, for no reason.

The employer is a collection agency, not your accountant

I have made the practical case for this already, in more detail, in Employee W-4 and Employer Duties: the employer works from the W-4 on file and the current tables, nothing more, and the annual “why didn't you withhold enough” complaint belongs at the employee's own desk, not the employer's. Worth repeating here only because it is the sharpest example of the same judgment call running the other direction — not a company deciding what is worth mentioning, but an employee deciding what got blamed on the wrong person.

Close enough, here, is not a shrug. It is the honest description of what withholding was built to do: collect roughly enough, from the information the employer was actually handed, so that filing season is a reconciliation instead of a referendum on who did their job. When the number does not land on zero, that is not proof anyone failed. It is proof the system worked exactly as designed — and a reminder of the one line on that form that only the employee gets to fill in.

See also: Employee W-4 and Employer Duties and Why Is My Withholding Zero?