The IRS 1040 is the form used in tax filings pertaining to a personal or individual income tax. All individuals who are residents of the United States can use the 1040 to file their taxes with Internal Revenue Service. The IRS 1040 is accessible in 3 primary types - the 1040, 1040A, and 1040EZ. The 1040EZ, as denoted by its name, is the simplest of the three IRS 1040 forms. For those who qualify, the 1040EZ can be completed with much greater ease. In order to qualify, the person cannot have dependents, be over 65, make more than $100,000 a year, or make certain types of claims on their taxes. The next level up, the 1040A, is restricted to individuals who do not itemize, make under 100,000, receive income from qualified sources, only file certain types of claims, and only file certain types of adjustments. The base, or "long" 1040 form is the longest option, consisting of two pages in itself and additional schedules tat can be added. The long 1040 can generally be filed by anyone filing an filing a personal income tax.