Common tax forms every employer needs to know

Executive overview

Employers and HR teams must handle several tax forms correctly or face penalties and compliance failures. Six forms cover most payroll and contractor situations: 1040, W-4, W-9, W-2, 1099, and 1095-C.

Each form has a specific trigger — the wrong form, or the right form filed late, creates tax liability for the employer or employee.

Get the form right at the start of the relationship, not after work begins.

The six forms

1. Form 1040 — Annual income tax return filed by individuals. Four variants: standard 1040 (most people), 1040-SR (age 65+, larger font), 1040-NR (resident aliens), 1040-X (amending a previously filed return).

2. Form W-4 — Completed by new employees at hire. Tells the employer how much federal tax to withhold each pay period. Under-withholding triggers a tax bill for the employee; over-withholding means they took home less than they could have. Accuracy at onboarding prevents both outcomes.

3. Form W-9 — Required from any independent contractor, freelancer, or vendor paid by the organisation. Captures name, address, and tax ID. Request it before work begins — waiting until after creates potential withholding tax liability for the employer.

4. Form W-2 — Issued to all employees, showing total wages and taxes withheld (federal, state, local). Must be distributed by 31 January each year. The send date, not the receipt date, determines compliance.

5. Form 1099 — Used by contractors and freelancers to report non-employee income. Employers must issue a 1099-NEC to any contractor or freelancer paid $600 or more. Deadline is also 31 January.

6. Form 1095-C — Required from applicable large employers (ALEs). Documents that health insurance coverage was offered to full-time employees who worked one or more months during the year.