A W-9 is an IRS form used by businesses and other entities to collect taxpayer identification numbers from independent contractors and individuals.

IRS Form 941 is a form businesses file quarterly to report taxes they withheld from employee paychecks. Filing deadlines are in April, July, October and January.

IRS Schedule K-1 is a document used to describe the incomes, losses, and dividends of a business's partners or an S corporation's shareholders.

IRS Form W-2G is an Internal Revenue Service document sent to gamblers to report their winnings and the amount that was withheld for taxes at the time of the payout.