Do only one of the following.
A. Use the estimator at www.irs.gov/W4App for most accurate withholding for this step (and Steps 3–4); or
B. Use the Multiple Jobs Worksheet on page 3 and enter the result in Step 4 below for roughly accurate withholding; or
C. If there are only two jobs total, you may check this box below. Do the same on Form W-4 for the other job.