The W-4 Step 2 checkbox, explained with numbers
Step 2 of Form W-4 is for people with more than one job at the same time, or married couples filing jointly where both work. Checking the box tells each employer to withhold as if that job's pay is only part of your household income.
What changes
The IRS uses a separate set of withholding tables for checked boxes. They roughly halve the standard deduction and narrow each tax bracket, so each job withholds more.
Worked example (2026)
A single worker earning $40,000 a year, paid every two weeks, in a state with no income tax:
| Federal tax / check | Take-home / check | |
|---|---|---|
| Box not checked | $100.77 | $1,320.00 |
| Box checked | $168.65 | $1,252.12 |
If you really have two $40,000 jobs, checking the box on both is what stops a surprise tax bill in April. If you only have one job, checking it just means a bigger refund later.
Try both settings in the calculator →
General information, not tax advice.