The short answer is: sometimes, but with significant limitations. The IRS’s e-file system is designed primarily for current-year returns, and electronic filing for prior years becomes more restricted the further back you go.

Understanding exactly when online filing is possible, what software supports it, and when paper filing is required helps you plan your approach to catching up on missing returns.

IRS E-File Limitations for Prior Years

The IRS e-file system processes returns in real time, and it only supports returns that match the current or recent processing cycles. There are hard limits on how far back you can go with electronic filing.

The Two-Year Electronic Filing Window

The IRS generally allows e-filing for the current tax year and the two immediately prior tax years. For example, during calendar year 2025, you can typically e-file returns for tax years 2022, 2023, and 2024 through IRS-approved software. Once a tax year falls outside this two-year window, electronic filing is no longer available for that year through the IRS e-file system.

This is a firm technical limitation – tax software cannot e-file a return that the IRS system does not accept. Even if you prepare a 2020 return accurately using prior-year software, you cannot transmit it electronically to the IRS. It must be mailed.

The IRS E-File Shutdown Period

The IRS typically shuts down its e-file system for a period of several weeks each winter – usually from late November to mid-January – to perform system updates and prepare for the new filing season. During this period, no returns can be e-filed, including current-year returns. If you are attempting to file during this window, you will need to wait for the system to reopen or mail the return.

State Returns Follow Similar Rules

Most state e-file systems mirror the federal e-file limitations. If you cannot e-file a federal return for a given year, you typically cannot e-file the corresponding state return either. State deadlines and e-file availability vary – check your state’s department of revenue for specifics.

Software That Supports Back Tax Filing

Even though e-filing is limited to recent years, tax software is still useful for preparing prior-year returns that will be filed by mail. The right software for each situation depends on how many years back you need to go.

Current-Year Software With Prior-Year E-File

Major tax software providers – TurboTax, H&R Block, TaxAct, FreeTaxUSA – all support e-filing for the current year and typically one to two years back. During the active e-file season, this means you can prepare and electronically file returns for recent missing years without mailing anything. This is the most convenient option for recent missing years.

Downloadable Prior-Year Software

For returns that are outside the e-file window but are recent enough to be supported, major software providers sell downloadable prior-year versions. TurboTax sells downloadable software for prior years. H&R Block offers a similar product. These programs use the correct forms for the specific tax year and can handle most return types, though returns prepared with this software must be printed and mailed.

Coverage typically extends back three to five years for downloadable software. Returns older than this may need to be prepared using IRS paper forms directly.

Online Tax Preparer Services

Some online tax preparation services and paid professional platforms support prior-year return preparation for a fee. These typically cover two to four years back. In some cases, an enrolled agent or CPA working on your behalf may use professional tax software that supports more years than consumer software.

IRS Forms Directly

For returns older than what any software supports, the IRS provides all prior-year forms and instructions at IRS.gov/forms-pubs. You can download the correct Form 1040 and all applicable schedules for any prior year and complete them manually or in a PDF editor. This is the most labor-intensive approach but works for any year regardless of how old it is.

When Paper Filing Is Required

Paper filing is required in specific situations regardless of how recent the return is.

Returns More Than Two Years Old

As described above, any return more than two filing years old cannot be e-filed. These returns must be prepared and mailed to the IRS. No exceptions.

Returns Flagged by the IRS

In some cases, the IRS may flag your account in a way that prevents e-filing even for recent years – for example, if there is identity verification issue on your account or if certain return types are involved. If an e-file attempt is rejected for reasons other than a typo or data error, paper filing is the alternative.

Certain Return Types

Some return types are not eligible for e-filing under any circumstances. Amended returns (Form 1040-X) are generally not eligible for e-file for prior years, though the IRS has been expanding e-file availability for amended returns in recent years. Check current IRS guidance for the specific return type you are filing.

Foreign Taxpayers and Non-Standard Situations

Taxpayers with foreign addresses, certain international tax situations, or other non-standard circumstances may find that e-filing is unavailable or complicated. Paper filing is the reliable fallback for any situation the e-file system cannot handle.

Step-by-Step Filing Guidance

Here is a practical walkthrough for filing prior-year returns, whether online or by mail.

Step 1: Pull Your IRS Transcripts

Before preparing any return, download account and wage/income transcripts from IRS.gov. This shows exactly what the IRS has on file – which years need returns, what income was reported by third parties, and whether any Substitute for Returns have been processed. This step is the same regardless of whether you will be filing online or by mail.

Step 2: Gather Income and Deduction Records

Collect all income documents (W-2s, 1099s) and deduction records (mortgage interest, charitable contributions, business expenses, etc.) for each year you are filing. If original documents are unavailable, the Wage and Income Transcript provides the income data you need.

Step 3: Choose Your Filing Method

Based on the year involved:

• Within 2 years: Use current-year software to e-file (most convenient, often free or low-cost)
• 2 to 5 years back: Use downloadable prior-year software and mail the completed return
• More than 5 years back: Download IRS prior-year forms from IRS.gov/forms-pubs and complete manually, then mail

Step 4: Prepare the Return Using the Correct Year’s Forms

Regardless of method, make sure you are using the correct forms for the year being filed. The Form 1040 and schedules changed substantially in 2018. Prior-year software handles this automatically. If using IRS forms directly, download the specific year’s Form 1040 from IRS.gov/forms-pubs.

Step 5: File in Chronological Order When Filing Multiple Years

If you are catching up on multiple years, prepare and file from oldest to most recent. Some figures carry forward from year to year – capital losses, net operating losses, depreciation – and filing in order ensures accuracy across all returns.

Step 6: For Paper Returns, Mail Each Year Separately

Mail each year’s return in a separate envelope to the correct IRS address for that filing type (check the instructions for that year’s Form 1040 for the address). Use certified mail with return receipt requested. Keep a complete copy of each return and all supporting schedules.

Step 7: Track Processing and Follow Up

E-filed returns are typically processed within one to three weeks. Mailed returns take four to eight weeks. After that time, you can check your IRS account transcript to confirm the return was received and processed. If your account has not been updated, you can call the IRS to confirm receipt or check the status of processing.

What to Do After Filing

Once your returns are filed and processed, the IRS will update your account. If you are owed a refund for years still within the three-year window, the IRS will issue it – typically by mail as a check for prior-year returns, though direct deposit may be possible for recent e-filed returns.

If you owe a balance, you will receive a notice showing the amount due with penalties and interest. At that point, contact the IRS to arrange a payment plan if you cannot pay in full. You must be filing-compliant before the IRS approves most payment arrangements, so getting all your returns filed is the prerequisite for accessing payment programs.

Summary

Online filing for back taxes is available for the current year and approximately two years prior. Returns older than that cannot be e-filed and must be mailed. Tax software supports prior-year return preparation for several years back; older years require IRS paper forms downloaded from IRS.gov/forms-pubs. Whether filing online or by mail, the process is the same: pull IRS transcripts first, gather income and deduction records, prepare returns in chronological order, and address any balance through IRS payment programs after filing.