Gather tax documents for each year you need to file
Get the correct tax forms for each past year
Complete a separate return for each tax year
Use the tax rules and rates that applied for that year
Check whether you are due a refund or owe taxes
File each return by mail if e-filing is not available for that year
Attach any required supporting forms or schedules
Sign and date each return
Keep copies of all filed returns and documents
Pay any taxes owed as soon as possible
Contact the IRS or a tax professional if you need help with missing records or special situations