The GOP tax scam messed up people's withholding — and the incoming fix from the IRS will be a nightmare

If your tax returns are about to go through, be warned: the whole process might be about to give you another headache.

According to USA TODAY, the IRS is about to launch a release a new W-4 form to calculate paycheck withholding, the system with which most salaried workers have their tax payments deducted from their income as they receive it.

The new change comes after numerous problems with withholding in the wake of the GOP tax cut bill, which in many cases reduced people's withholding by too much. As a result, some people who were expecting a refund got hundreds or thousands less than they were expecting — and some actually owed the IRS more money.

The IRS' new W-4 form, in theory, will ensure complete accuracy for withholding going forward, meaning that no one will either owe money or be due a refund in the future.

But the new form will be a nightmare to figure out for taxpayers, says ADP executive Pete Isberg: "The accuracy will be 100 percent, but the ease-of-use will be zero."

In fact, the form will reportedly be so complicated — asking employees in advance to calculate their nonwage income, deductions, tax credits, and income from second and third jobs in the household for the whole upcoming year — that it could essentially be like having to file your tax return a second time.

If you thought taxes are frustrating to do now, it may be nothing to what's coming up next.