These people should pay especially close attention to their withholding:
Filers who itemize: Prior to the new tax law, it may have made sense to withhold less from your pay if you itemized deductions.
That may no longer be the case now that the standard deduction has nearly doubled to $12,000 for singles and $24,000 for married couples filing jointly. Those who itemized in the past may no longer do so going forward, so they may need to revisit their withholding.
Households with dependents: Under the old law, it may have made sense to withhold less in taxes if you had dependents.
Now, personal and dependent exemptions are out, so these filers should review their paystubs to ensure that they’re not underwithheld.
Retirees: Just because you’re no longer working, doesn’t mean that you still won’t owe. You can use Form W-4V to withhold a flat rate from your Social Security check or Form W-4P to withhold from your pension.