We didn’t withhold! How do we fix it?

Q. A new employee was mistakenly paid through Accounts Payable for January, so no federal or state taxes were withheld from his pay. It’s still early in the year, so we’d like to take out the taxes that should have been withheld from later wage payments. But we don’t want to leave him with no net pay. According to our calculations, it should take us two months to withhold the additional taxes. Is this OK?