Federal and state law require you to keep specific payroll records for several years. The IRS can audit payroll tax returns going back at least three years, but keeping records for four years is the safer practice since audits can extend further if they find issues.

Start with employee information collected at hire. Form W-4 tells you how much federal tax to withhold. Massachusetts requires Form M-4 for state withholding. Form I-9 verifies employment eligibility and has its own retention rules. Keep I-9s for three years after the hire date or one year after employment ends, whichever is later. These forms should be accessible quickly if someone asks for them.

Pay records need to show how you calculated each paycheck. Keep timesheets or time records, hourly rates or salary amounts, hours worked each day and week, overtime calculations, gross pay, all deductions itemized, and net pay. You also need to document pay dates and the pay period each check covers. Most payroll software generates reports that capture all of this, but you need to actually save those reports.

Tax records include every quarterly Form 941 you file with the IRS, annual Form 940 for unemployment tax, W-2s you issue to employees, and W-3 transmittal forms. Massachusetts requires quarterly wage reports filed with the Department of Revenue. Keep copies of everything you file and proof of payment for any taxes remitted.

Full-service payroll providers typically store records electronically, but you should download and save your own copies. If you switch providers or they go out of business, you need access to historical records.

Benefits documentation matters too. If you offer health insurance, retirement contributions, or other benefits, keep records showing what you contributed and what employees paid. These affect taxable wages and get questioned during audits.

The Department of Labor requires certain records to be kept for three years and others for two years under the Fair Labor Standards Act. The four-year rule for tax purposes covers most situations, so defaulting to four years keeps you compliant across the board.

Store records digitally with backups. Paper files get lost, damaged, or take up space you don’t have. Scanned copies organized by year and document type are easier to search when you need something. Make sure backups happen automatically so you don’t lose years of records to a hard drive failure.

The cost of poor record keeping shows up during audits. If you can’t prove what you paid, when you paid it, and how you calculated withholding, you’re at the mercy of whatever the auditor reconstructs. That rarely works in your favor. Small business bookkeeping in MetroWest Massachusetts includes setting up systems that capture these records correctly from the start rather than scrambling to recreate them later.