Letters and Notices

The Illinois Department of Revenue (IDOR) sends letters and notices to request additional information and support for information you report on your tax return, or to inform you of a change made to your return, balance due or overpayment amount.  

Read your notice or letter in its entirety and it will explain the reason for the contact and give you instructions on how to respond, if necessary.  Most of the time if you agree with the information, there is no need to contact us.

• Online
  For tax years 2019 and after, if you received one of the letters listed below, you can now submit your support through MyTax Illinois, our online account management program. Support submitted through MyTax Illinois is secure and may help avoid delays associated with information submitted by mail. For more information and instructions, visit MyTax Illinois Help Guide - Respond to a Notice. You can also use MyTax Illinois to check your account balances or view any notices sent to you. To respond through MyTax Illinois, simply login to your existing account or create a new account at mytax.illinois.gov.  Note: Activate your MyTax Account within 90 days of the date on your letter or notice. After this time period, you will be required to request a new Letter ID to activate your account. You may use most letters sent from IDOR to create a new logon.
• By Mail
  You may also mail your response to the address listed on the letter.

Important: Make sure to respond by the specific due date on the letter or notice to minimize additional interest and penalties and preserve your appeal rights if you do not agree.

If you have a balance due, pay as much as you can, even if you can't pay the full amount you owe. You can pay online or by mail.  Visit our Payments page for more information.

It's important to keep a copy of all notices or letters with your tax records. You may need these documents at a later date.

The following are common letters that IDOR sends to taxpayers.

• Return Correction Notice (IDOR-1-RCN) – These letters are sent when there is a question on the information you supplied on your Illinois income tax return. The letter includes an explanation and gives guidance on how to resolve the issue.  Respond to the letter with the information requested. Note: If you received a Return Correction Notice requesting completion of an Illinois Income Verification Questionnaire or an Illinois Residency Verification Questionnaire and did not receive the questionnaire, you can print the questionnaires below.
  • Illinois Income Verification Questionnaire
  • Illinois Residency Verification Questionnaire
• Identity Verification Letter (LTR-425-C, LTR-425-D, and LTR-425-Q) – These letters are sent to confirm your identity and make sure we are issuing refunds to the correct taxpayer. Follow instructions on the letter. For information about how to respond to an identity verification letter, see Identity Verification Letters Information page. Note: LTR-425-C, LTR-425-D, and LTR-425-Q cannot be used to create a MyTax Illinois logon.
• Notice of Tax Due (IDOR-2-BILL) – This letter is sent when there is a balance due on your account. Visit our Payments page for more information.
• Taxpayer Notification Response (LTR-402) – These letters notify you of receipt of the information you sent and if additional information is needed, your account was updated, or if you have a balance due or refund. If requested, respond to the letter with the information requested.
• Taxpayer Notification Response (LTR-402-X) -These letters notify you of receipt of your amended return and the information you sent. These letters also include if additional information is needed, your account was updated, or if you have a balance due or refund. If requested, respond to the letter with the information requested.
• Notice of Claim Denial (LTR-405) - These letters notify you of the denial of your claim for refund. If needed, visit our Payments page for options for payment.
• Notice of Deficiency (LTR-393-IPD) - These letters notify you of a balance due over a certain amount of time. If not paid, you may be referred to our collections department. Visit our Payments page for options for payment.
• Erroneous Refund Letter (LTR-359-IPD) - These letters notify you of a refund sent to you in error. Respond to the letter with the information requested.
• Support for Abatement Request (LTR-202) – These letters notify you of the results of your request for abatement of penalties.
• Account Status (LTR-433) – These letters notify you of your Illinois income tax account’s status, usually verifying the account to be in good standing. You do not need to respond to this letter. If you have an overpayment, it will be refunded in the method you requested. 

An estimated payment penalty is assessed on your income tax amount if you did not make timely estimated tax payments. Estimated tax payments are required quarterly on your income if you will owe $1,000 or more in Illinois income tax at the end of the year, and you do not have enough tax withheld on your income. Estimated payments are due on April 15, June 15, September 15, and January 15 of every year.  If any of the payments are late or less than the amount required, you may be assessed a penalty for late payment of estimated tax.

If you earn income from which there is no tax withheld, it is your responsibility to make quarterly estimated tax payments on this income. 

For more information about estimated payments, please refer to Publication 105, Illinois Estimated Payment Requirements for Individuals and Businesses, Instructions for line 33 of the IL-1040, Form IL-2210, Instructions for Form IL-2210 and Form IL-1040-ES.