Filing your Illinois return electronically is the fastest and most secure way to file your state tax return. Most taxpayers can e-file through TaxSlayer, and electronic filing helps reduce errors, provides confirmation that your return was received, and may speed up refund processing. Illinois encourages taxpayers to file electronically whenever possible.
Who Can E-File an Illinois Return?
Most Illinois taxpayers are eligible to electronically file Form IL-1040 through approved tax software. Eligibility depends on your filing status, residency status, and the forms included with your return.
You may be asked to verify your identity during the Illinois e-file process. The information required depends on whether you have previously e-filed an Illinois return.
Illinois Electronic Signature Requirements
Illinois requires taxpayers to electronically sign their return before it can be transmitted.
If you have previously e-filed an Illinois return and have an Illinois Signature PIN, you may be asked to provide either:
- Your Illinois Signature PIN, or
- Your prior-year Illinois AGI (Adjusted Gross Income) from Form IL-1040
Providing one of these items allows Illinois to verify your identity and electronically sign your return.
If you are filing your first Illinois return, do not know your Illinois Signature PIN, or have not e-filed enough prior Illinois returns to use the PIN method, Illinois may require information from your Illinois driver's license or state-issued ID.
How to Complete the Illinois E-File Authorization
If You Have an Illinois Signature PIN
Navigate to the Illinois e-file section and select the option indicating that you previously e-filed an Illinois return and have an Illinois Signature PIN.
You may see a screen similar to the following:
- Illinois Signature PIN
- Illinois Prior Year AGI (Line 1 of the prior-year IL-1040)
Enter the requested information exactly as it appears on your Illinois records.
If You Do Not Have an Illinois Signature PIN
If you are filing an Illinois return for the first time, cannot locate your Illinois Signature PIN, or do not meet Illinois requirements to use the PIN method, you may need to provide information from your Illinois driver's license or state-issued ID.
Enter the information exactly as it appears on the identification document, including:
- Driver's license number
- First name
- Middle name (if shown)
- Last name
- Suffix (if shown)
- Other requested identifying information
Any mismatch between the information entered and state records may cause your return to be rejected.
Program Path
To access the Illinois e-file authorization screens:
State Section > Illinois Return > E-File Information
The screens presented will vary based on your responses to the Illinois e-file signature questions.
Common Questions
What is an Illinois Signature PIN?
An Illinois Signature PIN is an electronic signature credential used by the Illinois Department of Revenue to verify your identity when e-filing your state return.
What if I don't know my Illinois Signature PIN?
If you cannot provide your Illinois Signature PIN, the program may allow you to verify your identity using another approved method, such as prior-year Illinois AGI or Illinois driver's license information.
Can I e-file without an Illinois driver's license?
In many cases, yes. Illinois may accept other approved identity verification methods depending on your filing history and circumstances.
What happens if my Illinois return is rejected?
Review the rejection message carefully and verify that:
- Your Illinois Signature PIN is correct.
- Your prior-year Illinois AGI matches the amount reported on your Illinois return.
- Your driver's license or state ID information was entered exactly as shown on the card.
- Your name and Social Security number match government records.
After correcting the issue, retransmit the return electronically.
Helpful Tips
- Enter all identity verification information exactly as it appears on your Illinois records.
- Do not guess your Illinois Signature PIN or prior-year AGI.
- Use your Illinois driver's license or state ID when completing identity verification screens.
- If your return is accepted electronically, do not mail a duplicate paper return unless specifically instructed by the Illinois Department of Revenue. Multiple filings can delay processing.
- Keep a copy of your accepted return and transmission confirmation for your records.
After Your Return Is Accepted
Once Illinois accepts your e-filed return:
- Save or print your filing confirmation.
- Monitor your refund status through the Illinois Department of Revenue's "Where's My Refund?" tool.
- Retain copies of your tax return and supporting documents with your records.