Gather all missing tax documents for each year you need to file
Request wage and income transcripts from the IRS if you do not have your forms
Get account transcripts to see what the IRS already has on file
Collect records for deductions, credits, business income, and expenses
Use the correct tax forms for each specific tax year
Complete one separate return for each year you are filing
Make sure each return uses the tax laws and rates for that year
Sign and date each return
Mail paper returns to the IRS, since most past-year returns cannot be e-filed
Include any required state tax returns for each year
Pay any taxes owed as soon as possible
Set up a payment plan if you cannot pay the full amount
File as soon as possible to reduce penalties and interest
Keep copies of all returns, forms, and payment records
Check whether you are due a refund before filing
Verify the filing deadline for each year to avoid losing a refund
Contact a tax professional if you have multiple years, business income, or missing records