Internal Revenue Service forms are the documents that taxpayers must fill out when filing their taxes, and IRS publications explain the rules for filling out the forms, according to the IRS. The IRS publishes different forms and publications for individuals and businesses.
The standard tax form filled out by individual taxpayers is the 1040, and simplified versions exist for people who do not have complex finances, explains the IRS. Individuals also fill out form W-4 to arrange for tax withholding from their paychecks, and Form 2848 allows another individual to represent a taxpayer before the IRS. Businesses file W-2 forms for each employee from whom taxes were withheld. Publication 15 explains to businesses their tax-paying responsibilities.