ST‑556-X Amended Sales Tax Transaction Return Instructions

You must file Form ST-556-X if you are a registered retailer or leasing company who files Form ST-556, Sales Tax Transaction Return, to report sales at retail in Illinois of items are of the type that must be titled or registered by an agency of Illinois state government (e.g., vehicles, watercraft, aircraft, trailers, manufactured (mobile) homes), and if you need to:

• correct your Form ST-556 to pay more tax;
• request a credit for overpaid tax (Do not file Form ST-556-X for amounts less than $1. Do not use the credit until we notify you that your credit has been approved.);
• respond to a bill or notice; or
• make corrections to line items but not change the amount of tax due.

Note: Effective January 1, 2025, sellers of the following items to lessors for the purpose of renting or leasing the items are authorized to sell the items as a nontaxable sale for resale (Exemption 5(b)):

• trailers that must be registered with an agency of this State, other than semitrailers as defined in Section 1-187 of the Illinois Vehicle Code; and
• items that must be titled with an agency of this State but not registered with an agency of this State, such as all-terrain vehicles (“ATVs”) and off-road motorcycles.

Effective January 1, 2025, persons engaged in the business of renting or leasing these items are subject to Illinois Sales and Use Tax and must report and pay tax on their rental or lease receipts as they are collected from the customer. Rentors and lessors of these items should not use Form ST-556 or Form ST-556-LSE to report rental or lease receipts from these items. Instead, rentors and lessors of these items should use Form LSE-1 to report these rental or lease receipts.

If you received a notice from us that your original return is unprocessable, we cannot process an amended return (claim for credit) until you respond to the notice.

Do not file this return if you repossessed a vehicle. Instead, you must file Form ST-557, Claim for Credit for Repossession of Motor Vehicles, Watercraft, Aircraft, Trailers, and Mobile Homes.

The period for which you can claim a credit for an overpayment depends on when you file your Form ST-556-X. If you file this amended return between January 1 and June 30 of this year, you may file a claim for credit for the amounts you overpaid during the current year and previous 36 months. Beginning July 1, you may file a claim for the amounts you overpaid during the current year and the previous 30 months.

Note: Effective June 25, 2021, for any period included in a claim for credit or refund for which the statute of limitations for issuing a notice of tax liability under the Retailers’ Occupation Tax Act will expire less than 6 months after the date a taxpayer files the claim for credit or refund, the statute of limitations for issuing a notice of tax liability is automatically extended for 6 months from the date it would have otherwise expired.

If you are making an additional payment, please note that the longer you wait to pay, the more interest and, when applicable, penalty you will owe. For more information about penalties and interest, see Publication 103, Penalties and Interest for Illinois Taxes, available on our website at tax.illinois.gov.

Form ST-556-X must be filed electronically through MyTax Illinois at mytax.illinois.gov if the original Form ST-556, Sales Tax Transaction Return, was filed electronically through MyTax Illinois.

If the original Form ST-556 was filed electronically using an approved service provider in the Electronic Registration and Title (ERT) program or was filed using a preprinted paper form, you need to file a paper Form ST-556-X to make changes to an original Form ST-556. Mail completed paper returns to:

ILLINOIS DEPARTMENT OF REVENUE
PO BOX 19034
SPRINGFIELD IL 62794-9034

The retailers’ allowance (discount) is an amount that retailers may claim only if the return is filed on or before the due date and only for a percentage of the taxes paid on or before the due date. This discount is allowed as a reimbursement for the expenses incurred in keeping records, preparing and filing returns, remitting the tax, and supplying data to the Illinois Department of Revenue (IDOR) on request.

For all Forms ST-556-X filed to amend original returns due on or after January 1, 2025, the discount is limited to $1,000 per month for all returns (i.e., both Forms ST-556 and ST-556-LSE and amended returns) filed that month. The $1,000 monthly cap applies to vehicle sales with a delivery date on or after December 12, 2024, which corresponds to returns due on or after January 1, 2025. Retailers will no longer be able to reduce the tax remittance by the amount of the retailers’ allowance when filing Forms ST-556 and ST-556-LSE. To avoid potential billing issues or confusion, IDOR will calculate the discount on these returns through a monthly reconciliation process that will occur approximately 60 days after the end of a monthly liability period. The retailers’ allowance will be issued once the reconciliation process is completed each month.

If you are not mandated to file Forms ST-556 and ST-556-LSE electronically and file using paper returns, do not enter a figure on the retailers’ allowance line. You must remit all tax reported as due on your return to be issued the retailers’ allowance, as applicable, through IDOR’s monthly reconciliation process.

If you need help, call our Taxpayer Assistance Division weekdays between 8:00 a.m. and 5:00 p.m. at 1 800 732-8866, 217 782-3336, or 1 800 544‑5304 (TTY).

You may also visit our website at tax.illinois.gov.

Language assistance services are available upon request and are free of charge.

See ST-9, A Guide for Reporting Sales Using Form ST-556, Sales Tax Transaction Return, available on our website at tax.illinois.gov, for additional guidance.

Everyone must complete Steps 1, 2, and 4. You must also complete Step 3 if you are changing financial information.

Step 1: Identify the return you are amending and your business

Line 1: Enter the tax return number that appears on your original Form ST-556.

Lines 2 through 4: Enter your Illinois account ID number as it appears on your original Form ST-556. Also, enter the name of your business as it appears on your original return. Next, enter a daytime phone number for your business.

Step 2: Mark the reason why you are filing an amended return

Mark the reason (1 through 8) that best reflects why you are filing an amended return for your original Form ST-556.

Line 4a: If you issued a drive-away permit, enter the drive-away permit number and the two-letter state abbreviation on the lines provided. If the purchaser transferred current out-of-State plates to the item sold, enter the license plate number and the two-letter state abbreviation on the lines provided. Do not mark this reason if you sold the item to an out-of-State dealer for resale.

Note: Dealers claiming the “nonresident purchaser” exemption should keep a copy of the purchaser’s valid out-of-State drivers license in their books and records as proof of nonresidency. You also are responsible for obtaining a signed certification documenting the purchaser’s eligibility for the nonresident purchaser exemption.

As a condition of claiming this exemption, nonresident purchasers must certify that they are not residents of Illinois. See ST-588, Nonresidency Exemption Certification for Sales and Leases of Motor Vehicles and Trailers, available on our website at tax.illinois.gov. Retain this certification in your records as proof that no tax was due on the sale of the specified item.

Line 4b: Enter the purchaser’s (dealer’s) account ID number on the line provided. If you sold to an out-of-State dealer, enter “Out-of-State Dealer” in the space provided for the account ID number.

Line 4c: Enter the organization’s active Illinois Sales Tax Exemption “E” number on the line provided.

Line 4d: Enter the certificate of authority number on the line provided. Keep a properly completed Form RUT-7, Rolling Stock Certification, in your books and records for documentation.

Line 4e: Enter the purchaser’s account ID number on the line provided.

Line 4f: Enter an explanation on the lines provided. Attach additional sheets if necessary.

Line 5: Enter the correct information on the lines provided.

Line 6: Enter the correct taxable location name on the line provided.

Line 7: Enter the tax return number of the Form ST-556 or Form ST-556-LSE on which tax was previously paid for this same item to an Illinois retailer or the tax return number of the Form RUT-25 or Form RUT-25-LSE on which tax was previously paid for this same item directly to the Department.

Line 8: Mark 8 only if 1 through 7 do not apply. Enter an explanation on the lines provided. Attach additional sheets if necessary.

Step 3: Correct your financial information

Complete Step 3 to make corrections to the financial figures on your return. Round your figures to whole dollars by dropping amounts of less than 50 cents and increasing amounts of 50 cents or more to the next higher dollar.

For Line 4, enter the appropriate tax rate for your area on the line provided.

If you were assessed penalty and interest on the original Form ST-556 that you filed, we will take those figures into account when we compute your amended return.

Note: Do not include penalty and interest in the figures you enter in any of the lines in Step 3.

Column A

Lines 1 through 14: Enter the figures from your most recent return. These figures may be from your original Form ST-556 or a previously filed Form ST-556-X.

Column B

Lines 1 through 14: Enter the corrected figures. If there is no change from Column A, enter the figures from Column A.

Note: If you have an amount entered in Column A that you are reducing to zero, enter “0” in Column B. Leaving the line in Column B blank may delay the processing of your return.

Lines 15 through 17: Complete Column B only. Follow the instructions on the form.

Detailed instructions for certain lines in Step 3

Line 1: Enter the corrected selling price, including accessories, federal excise taxes, freight and labor, dealer preparation, documentary fees, and any rebates or incentives for which you as a dealer receive reimbursement. Clean vehicle credits that are applied toward the purchase of a clean vehicle should be included as part of the taxable selling price of the vehicle. Do not subtract the value of any rebate made directly to the customer. In general, any cost passed on to the customer as part of the sale of an item and for which gross receipts are received should be included in the total price.

Note: If you are selling a new truck that weighs 33,000 pounds or more or a new trailer or semitrailer chassis weighing 26,000 pounds or more, you may exclude the federal excise tax from the total price.

Line 2: For sales made on or after January 1, 2020, up to and including December 31, 2021, for purposes of calculating your Sales Tax due, you cannot claim trade-in credit exceeding $10,000 for any first division motor vehicle that was traded in during the sale being reported on Form ST-556-X. This means that $10,000 is the maximum credit a retailer may take on the return to reduce the taxable selling price of

a motor vehicle when the retailer accepts the trade-in of a first division motor vehicle in the transaction, regardless of the value of or credit given for the trade-in. This does not prohibit the retailer from reducing the price of the vehicle being sold by the value of or credit given for the traded-in motor vehicle. It only limits the credit the retailer may take on the return for that trade-in. For sales made on or after January 1, 2022, the $10,000 trade-in credit limit no longer applies.

Line 4: Calculate your tax due using the following to determine the appropriate rate:

• If you made this sale at your standard business location (i.e., the location printed on the front of the paper Form ST-556 returns the Department issues to you), multiply Line 3 by your standard tax rate.
• If you made this sale at an off-site location (e.g., a tent sale), follow the instructions on ST-23, How to Report Off-Site Sales on Form ST-556, Sales Tax Transaction Return, or Form ST-556-LSE, Transaction Return for Leases, available on our website at tax.illinois.gov.
• Clean vehicle credits that are applied toward the purchase of a clean vehicle should be included as part of the taxable selling price of the vehicle.

Note: If your sales location is in Cook, DuPage, Kane, Lake, McHenry, or Will County and the address of the party registering the item in Form ST-556, Section 1, is within the corporate limits of the city of Chicago, you must collect an additional 1.25 percent (.0125) Chicago Home Rule Use Tax. To help you calculate the tax due on one of these sales, we preprint a combined rate below Line 4 on the paper Form ST-556 returns the Department issues to you. This combined rate includes your tax rate, plus the additional 1.25 percent Chicago Home Rule Use Tax. To figure the correct tax due, multiply the amount subject to tax on Line 3 by the combined rate. Enter the result on Line 4.

Line 7: For all Forms ST-556-X filed to amend original returns filed on or after January 1, 2025, this discount for timely filing and payment is limited to $1,000 per month for all returns (i.e., both Forms ST-556 and ST-556-LSE and amended returns) filed that month. Do not enter a figure on Line 7. You must remit all tax reported as due on Form ST-556 or Form ST-556-X to be issued the retailers’ allowance, as applicable, through IDOR’s monthly reconciliation process.

For all Forms ST-556-X filed to amend original returns filed prior to January 1, 2025, complete this line only if you originally filed and paid the tax owed by the due date. If you filed on time, figure your discount at the rate of 1.75 percent (.0175) of the amount you paid on time.

If you are increasing the amount of tax due, you may not increase the amount of your discount unless the increased tax due is paid on or before the due date of the original return. If you are decreasing the amount of tax due, you will need to refigure the amount of discount to which you are entitled based on your new figures.

Line 7a:

Note: Use Line 7a only if you have a business location in the Metro-East Mass Transit District portion of St. Clair County.

The Illinois Department of Revenue is responsible for collecting and administering the fee imposed by the Metro-East Mass Transit District on items that will be title or registered in Illinois. Multiply Line 3 by 0.5 percent (0.005).

• If the result is less than $20, enter the result on Line 7a.
• If the result is $20 or more, enter $20 on Line 7a.

Line 10:

Requirements to claim credit for a previously leased item

If you are claiming a credit for previously paid taxes on Line 10, you must meet the following criteria:

The amount of tax paid on the purchase of this same item was paid to an Illinois retailer on Form ST-556 or Form ST-556-LSE or paid directly to the Department on Form RUT-25 or Form RUT-25-LSE when the item was purchased;

The amount of credit you are claiming on Line 10 for tax previously paid is equal to or less than the amount of the tax that was due on the Form ST-556 on or Form ST-556-LSE on which you reported your retail sale of the same item that you purchased;

• You did not take the credit on Line 10 of the Form ST-556 or Form ST-556-LSE at the time you sold the item and filed your return;
• You are now filing this Form ST-556-X to claim the credit to which you are entitled; and
• You have completed Step 2, Item 7 of this Form ST-556-X and have entered the tax return number of the Form ST-556 or Form ST- 556-LSE on which you previously paid tax for this same item to an Illinois retailer or the tax return number of the Form RUT-25 or Form RUT-25-LSE on which tax was previously paid for this same item directly to the Department.

Note: For items previously leased on or after January 1, 2015, you are only eligible to claim this credit if the selling price reported on the original Form ST-556-LSE or Form RUT-25-LSE was the actual selling price, not the amount of the lease contract, including the amount due at lease signing, plus the total amount of all lease payments.

Line 15: Enter the total amount you have paid. This figure includes the amount you paid with your original Form ST-556, any subsequent amended returns, and any assessment payments you have made. Be sure to reduce the total amount paid by any credit or refund of tax you have received for this transaction.

Line 16: If Line 15 is greater than Line 14, Column B, enter the difference on Line 16. This is the amount you have overpaid.

Line 17: If Line 15 is less than Line 14, Column B, enter the difference on Line 17. This is the amount you have underpaid. Pay this amount when you file the return. We will bill you for any additional penalty and interest that we calculate is due. Enter the amount you are paying on the line provided in the “Read this information first” section on the front of the return.

Step 4: Sign below

We cannot process this form until it is signed by the owner, officer, or other person authorized to sign the original return.

Penalty and Interest Information

If, on this amended return, you are increasing the amount of tax due, we will bill you for any additional penalty and interest that we calculate is due. If, on this amended return, you are reducing the amount of tax due or changing the due date, we will recalculate any penalty and interest that is due and include the recomputed amounts in determining the amount you have overpaid.

We will bill you for any amounts owed, including the following penalties and fees:

• You owe a late filing penalty if you do not file a processable return by the due date.
• You owe a late payment penalty if you do not pay the amount you owe by the original due date of the return.
• You owe a bad check penalty if your remittance is not honored by your financial institution.
• You owe a cost of collection fee if you do not pay the amount you owe within 30 days of the date printed on a bill that we send you.
• You owe a nonfiling penalty for transaction returns if you do not file a processable transaction return (ST-556, Sales Tax Transaction Return, or ST-556-LSE, Transaction Return for Leases) by the due date, but only if no tax is due on the return.

For more information, see Publication 103, Penalties and Interest for Illinois Taxes, available on our website at tax.illinois.gov.

ST-556-X Instructions (R-12/24)