How to Pay Your Illinois Income Tax Online
Where to pay Illinois income tax online
You can pay Illinois income tax online through the Illinois Department of Revenue website using their Online Payment System. The system accepts payments from a bank account (ACH transfer) or a credit or debit card. You do not need to create an account beforehand — you can pay as a guest, though creating one lets you save payment history and set up recurring payments.
The payment portal is at tax.illinois.gov. Look for the "Make a Payment" or "Pay Now" button on the homepage. You will need your Social Security number or Illinois tax ID, the tax year you are paying for, and the amount you want to send. The system will confirm your payment immediately and give you a confirmation number to keep.
If you filed a return and owe tax, you can also pay directly from your tax return before you file it electronically. This is often the fastest route because the payment and return move together through the system.
Key Takeaways
- The Illinois Department of Revenue Online Payment System accepts ACH transfers and card payments at tax.illinois.gov, and you can pay without creating an account.
- You need your Social Security number or tax ID, the tax year, and the payment amount — the system confirms your payment immediately with a confirmation number.
- ACH payments (bank account transfers) typically process within one to three business days; card payments post the same day but may carry a processing fee.
- If you owe tax on a return you have not yet filed, paying through your tax software before you file is usually faster than paying separately afterward.
- Payments made by the tax deadline (usually April 15) count as on-time even if they process a few days later, as long as you initiated them by the deadline.
ACH payments versus card payments
An ACH payment is a direct transfer from your bank account to the Illinois Department of Revenue. It is the cheapest option — there is no fee to you — and typically takes one to three business days to process. The money leaves your account within a day or two, so plan ahead if you are paying close to the deadline.
A card payment (credit or debit card) posts the same day you submit it, which is useful if you are paying at the last minute. However, the state does not charge the fee — the payment processor does, and it is passed to you. The fee varies but is usually between 2 and 3 percent of the amount you pay. For a $1,000 payment, that could be $20 to $30 extra. The state receives your full payment amount; the fee is on top.
If you have time before the deadline, ACH is almost always the better choice. If you are within a few days of the deadline and worried the payment will not clear in time, a card payment guarantees it posts the same day.
Payment deadlines and what happens if you miss them
Illinois income tax is due on April 15 each year, the same as federal tax. If you file an extension, the extension deadline is October 15, but tax is still due by April 15 — the extension only gives you time to file your return, not to pay. Payments initiated by April 15 count as on-time even if they do not process until a day or two later, as long as you started the payment before midnight on the deadline.
If you pay after April 15, the Illinois Department of Revenue charges interest on the unpaid amount. The interest rate is set quarterly and is based on the federal rate plus a state markup. Interest accrues from the original due date (April 15) forward, compounding daily. You will owe interest on top of the tax itself.
Late payments may also trigger a failure-to-pay penalty, which is typically 0.5 percent of the unpaid tax per month, up to 25 percent total. If you also filed your return late, you may owe a separate failure-to-file penalty as well. The longer you wait, the more these penalties and interest add up. If you cannot pay by April 15, paying what you can on time and the rest as soon as possible limits the damage.
Setting up a payment plan if you cannot pay in full
If you owe tax but cannot pay the full amount by the deadline, you can request an installment agreement with the Illinois Department of Revenue. This lets you pay in smaller amounts over time instead of one lump sum. You can request an agreement through the Online Payment System, by phone at 217-782-3336, or by mail.
The state will set up a payment schedule based on what you can afford and how much you owe. Monthly payments are common, though the exact terms depend on the amount and your circumstances. You will still owe interest on the unpaid balance, but setting up a plan before the deadline can reduce or eliminate the failure-to-pay penalty.
If you set up a payment plan, make your payments on time. Missing a payment can trigger collection action and may cause the state to revoke your driver's license or intercept a tax refund you are owed in a future year.
Tracking your payment and getting a receipt
When you complete a payment through the Online Payment System, you will see a confirmation number on your screen. Write this down or take a screenshot — it is your proof that you paid. The system also sends a confirmation email to the address you provide, though sometimes these emails take a few hours to arrive.
You can check the status of your payment by logging back into the Online Payment System with your Social Security number or tax ID. The system shows all payments you have made and their status (pending, processed, or applied to your account). ACH payments show as pending for a day or two, then move to processed once the money clears your bank.
Keep your confirmation number and any emails from the payment system. If there is ever a dispute about whether you paid, these documents prove you did and when. The state also has a record, but having your own copy protects you.
What to do if your payment fails or is rejected
An ACH payment can fail if your bank account does not have enough funds, if the account number is wrong, or if your bank flags the transaction as suspicious. A card payment can fail if the card is expired, if you have reached your credit limit, or if your bank declines the transaction for fraud protection.
If your payment fails, the Online Payment System will tell you why and let you try again with different information. You are not charged for a failed payment. However, if the failure means your payment does not go through by the deadline, you will owe interest and possibly penalties on the unpaid tax. Try to resubmit your payment as soon as you know it failed.
If you cannot figure out why a payment failed, call the Illinois Department of Revenue at 217-782-3336. They can look up your payment attempt and tell you what went wrong. Have your confirmation number ready if you have one.
Paying for prior years or amended returns
If you owe tax from a previous year — because you filed late, amended a return, or the state assessed additional tax — you can pay that through the same Online Payment System. When you start a payment, you will be asked which tax year the payment is for. Select the year that applies, and the payment will be credited to that year's account.
If you filed an amended return and now owe more tax, you can pay through the system the same way. The state will match your payment to your amended return based on your Social Security number and tax ID. If you are paying for multiple years at once, you may need to make separate payments for each year, or you can call the department to ask how to split one payment across years.
Frequently Asked Questions
Can I pay Illinois income tax by check or money order?
Yes. Mail your check or money order to the Illinois Department of Revenue at the address shown on your tax return or on the tax.illinois.gov website. Include your Social Security number and tax year on the check. Mailed payments take longer to process — usually two to three weeks — so mail early if you are close to the deadline. Online payment is faster and gives you a confirmation number the same day.
What if I pay too much by mistake?
If you overpay your Illinois income tax, the state will either refund the excess or credit it toward next year's tax, depending on what you request. You can indicate your preference when you file your return. If you overpaid through an online payment and have not filed your return yet, contact the Illinois Department of Revenue to let them know; they can apply the overpayment to the correct year.
Do I have to pay online, or can I use a tax preparer?
You do not have to pay online. A tax preparer or accountant can file your return and arrange payment on your behalf, often through their own payment system. However, you are responsible for making sure the payment is made by the deadline, so confirm with your preparer that they have submitted it. Paying online yourself gives you direct control and an immediate confirmation.
Will paying online affect my federal tax payment?
No. Illinois and federal income tax are separate. Paying Illinois tax online does not affect your federal payment, and vice versa. You will need to pay both separately, either through their respective online systems or by other means. The deadlines are the same (April 15), but the payments go to different agencies.
What if I cannot access the online payment system?
If the website is down or you cannot log in, you can pay by phone at 217-782-3336 or by mail. The phone line is available during business hours. If you are calling close to the deadline, expect longer wait times. Mailing a check is slower but always available. Keep a record of when you attempted to pay in case there is a question about whether you met the deadline.