A pay stub is one of the few financial documents almost everyone receives regularly, and one of the least understood. Most people look at the final deposit number, confirm it roughly matches what they expected, and move on. That's a habit worth breaking, because pay stub errors — a missed raise, a wrong tax filing status, a benefits deduction that never got updated — are common, and they're easiest to fix the month they happen.
Gross pay vs. net pay
Gross pay is everything you earned before anything is taken out: your salary or hourly wages, plus overtime, bonuses, or commissions for that pay period. Net pay — sometimes called "take-home pay" — is what actually lands in your bank account after taxes and deductions. The gap between the two is where most of the useful information lives.
The deduction section, line by line
Federal income tax withholding is based on the W-4 you filled out when you were hired (or last updated). State and local income tax withholding follow similar logic, if your state or city collects them. FICA taxes fund Social Security and Medicare and are calculated as a fixed percentage of wages, unlike income tax withholding, which depends on your elections.
Below that, you'll typically see pre-tax deductions — health insurance premiums, a traditional 401(k) or 403(b) contribution, an HSA or FSA contribution — subtracted before taxes are calculated, which is why increasing them lowers your taxable income. Post-tax deductions, like a Roth retirement contribution or a union due, come out after taxes are already calculated.
What's actually worth checking
- Your pay rate. After any raise, confirm the new rate shows up on the very next stub — payroll changes sometimes lag by a cycle, and it's easier to catch a missing raise in month one than to claim six months of back pay later.
- Your filing status and allowances. If you got married, had a child, or picked up a second job, your withholding elections may need an update — otherwise you could be over- or under-withheld all year.
- Recurring deductions. Anything that was supposed to be temporary — a benefits correction, a one-time repayment — should actually stop when it's supposed to.
- Year-to-date totals. Most stubs show YTD gross pay and YTD deductions. These are a fast way to sanity-check your annual numbers without waiting for a W-2.
When something looks wrong
Payroll departments deal with these questions constantly and it's rarely awkward to ask. Bring the specific stub and the specific line you're unsure about — "why did this deduction increase" is a much faster conversation than a vague "something looks off."
A pay stub isn't exciting reading, but it's one of the fastest financial documents to audit, and the errors it catches are usually free money — money that's already yours, just sitting in the wrong column.