Single/Married Filing Separately on your W-4, already? You know approximately how much you will owe ($400 based on your last year's taxes), so you can simply have the employer withhold an extra dollar amount each pay period. To break even - assuming that your income, deductions, etc. stay the same - you would divide last year's balance due, $400, by the number of paychecks remaining at the time you inform the employer. Most larger employers will want a new W-4. Here's how to fill it out: Keep everything else the same on your new W-4 and add the dollar amount to be withheld each pay period on Line 4(c) in Step 4.
