Form 1040
Annual income tax return filed by citizens or residents of the United States.

US Individual Income Tax Return – Form 1040 (PDF)

Form W-4
So your employer can withhold the correct federal income tax from your pay.

Employee’s Withholding Certificate – Form W-4 (PDF)

Form 1040-ES
Form 1040-ES is used by individuals with income not subject to tax withholding, to figure and pay estimated tax payments.

Estimated Tax for Individuals – Form 1040-ES (PDF)

Form W-9

Used to request a taxpayer identification number (TIN) for reporting on an information return the amount paid.

Request for Taxpayer Identification Number (TIN) and Certification – Form W-9 (PDF)