Gather all missing tax documents for each unfiled year
Request wage and income transcripts from the IRS if needed
Collect records for deductions, credits, and payments
Determine which tax years are unfiled
Get the correct tax forms for each year
Use the tax rules and rates for the specific year being filed
Complete each return separately for each tax year
Attach any required schedules and supporting forms
File the oldest unfiled return first if required by your situation
Submit paper returns for past tax years unless e-filing is available for that year
Mail each return to the correct IRS address
Include payment for any tax owed
Set up a payment plan if you cannot pay in full
File state past-due returns separately if required
Keep copies of every return and all supporting documents
Check for refunds before the statute of limitations expires
Respond promptly to any IRS notices after filing