Not tax advice. This is general information for truckers, not tax or legal advice. Rules, forms, tax rates, deadlines, refund limits, interest and penalties change and differ by state, so verify them with your base jurisdiction before you file; a qualified tax professional can also help.

How to Amend an IFTA Report: Fixing a Quarter You Already Filed

A fuel receipt turns up in the door pocket a month late. Miles got keyed under the wrong state. The quarter is already filed. What next?

The short answer: in the states below, a filed quarter is corrected with an amended return. New York says to use paper Form IFTA-100, and North Carolina says paper only. Illinois says that to change a processed return, a carrier must complete and submit an amended return. Washington says a return due within the last three years can be amended. IFTA's Articles of Agreement set the rules for credits, refunds and interest.

Here is what IFTA's manuals and five states' pages say, with a link to each so you can read the words yourself.

How do you amend a quarter in your base state?

Each state below says something different.

Base state	What the state says about amending
New York	Paper Form IFTA-100, marked with the quarter and year being corrected
North Carolina	Paper only
Illinois	To change a processed MFUT-15 return, complete and submit an amended return
Washington	A return due within the last 3 years can be amended
Texas	Use the rate chart for the quarter being amended

New York. New York's Web File page says amended returns go on paper Form IFTA-100, showing the quarter and year of the return being corrected.

North Carolina. The North Carolina Department of Revenue's 2025 motor carrier seminar slides say an amended GAS-1276 can be filed by paper return only.

Illinois. The MFUT-15 instructions say that to change a return Illinois has already processed, a carrier must complete and submit an amended return.

Washington. The Washington Department of Licensing's page says a carrier can amend a return that was due within the last 3 years.

Texas. The Texas Comptroller's pages we read say which rates to use on an amended quarter (more on that below) but not how to send the amendment in. For that, ask the Comptroller.

Based somewhere else? Your base jurisdiction's own pages or staff are the place to ask.

Do you show the difference or the whole quarter?

New York's form answers this one plainly. Form IFTA-100 says the amended return should show the correct figures for that quarter, not the difference, and an explanation of the changes must come with it.

So under New York's form, the amended report is the whole quarter done over, right, with a note saying what changed.

If you need a refresher on how a quarter is built from miles and gallons in the first place, see how to prepare a quarterly IFTA report step by step.

Which tax rates go on an amended quarter?

The Texas Comptroller says a licensee amending must use the tax rate chart for the specific quarter being amended. Under Texas's rule, that means the rates for that quarter, not the rates in force on the day the amendment is made.

For more on the quarterly rate charts, see our post on how IFTA rates change by quarter.

What happens if the fix shows you overpaid?

Fixing a quarter can turn up a credit. IFTA's Articles of Agreement (2025 edition, effective August 2025) lay out what happens to it.

• Credits and debits can net out. When filing, a licensee may apply an overpayment in one jurisdiction to tax owed to another and send the net amount to the base jurisdiction.
• A refund can be requested. The Articles say the licensee shall receive, on request, a refund of any accumulated credits.
• The request is in writing. Refund requests must be in writing unless the base jurisdiction has an automatic refund policy.
• No refund while tax is owed elsewhere. Refunds are made only when all tax liability, including audit assessments, has been settled with all member jurisdictions.
• 90 days to pay a refund that is due. A refund that is properly due is to be paid within 90 days of the licensee's request; if it is not, interest runs on it.

What if the credit is not refunded?

It rolls forward. Under the Articles, a credit that is not refunded is carried over to offset the licensee's tax in later quarters.

It does not roll forward for good. It carries until it is used up or eight calendar quarters have passed from the end of the quarter in which it arose, whichever comes first. New York's form also sets eight quarters: credit balances cannot be carried forward for more than eight quarters (two years) from the quarter the credit was earned.

How Texas handles credits

Texas spells out its own approach in Publication 96-336 (revised July 2025):

• Credits (overpayments) automatically transfer forward or backward to open IFTA tax liabilities.
• After open IFTA tax is paid, Texas refunds credits over $14.99 for a reporting period.

We did not find a minimum refund amount or an automatic refund rule for the other states in this article.

What happens if the fix shows you owe more?

Here the sources say less, and we will not say more than they do.

IFTA's rule on interest is that interest due from a tax return is worked out separately for each jurisdiction, from the date the tax was due, for each month or part of a month until paid. The IFTA rules we read do not say in so many words how that applies to tax that first shows up on an amended report. Not finding it written down does not mean no interest is owed; the base jurisdiction is the one to ask.

Washington's page speaks to it directly. It says that when an amendment raises the tax and the added tax is paid on time, only the added tax is owed. If it is paid late, Washington charges penalty and interest on the added tax under state law (RCW 82.38). For what Washington counts as late, see that page.

For how another base state charges interest on added tax, ask that state. Our post on IFTA filing deadlines and penalties in California and Texas covers late filing in those two states.

How far back can you amend?

The IFTA manuals we read do not set a deadline for amending as such. That does not mean there is no time limit. The nearest thing is a limit tied to record keeping.

The IFTA Procedures Manual says that unless the licensee has granted a waiver of the statute of limitations, no refund and no assessment for a shortfall can be made for a period for which the licensee no longer has to keep records.

How long records must be kept is covered in IFTA records: what to keep and for how long.

A state can set its own window too. Washington's three years, above, is Washington's rule, not IFTA's.

Can a records review lead to amended reports?

The IFTA Audit Manual says that when a records review finds non-compliant records, the jurisdiction should teach the carrier about record keeping and reporting and tell the carrier to file amended returns for returns already filed.

What happens in an audit is covered in what happens in an IFTA audit. What auditors look for on fuel receipts is in fuel receipt best practices.

What we could not find

Straight talk on the gaps, so you know where to ask:

• How Texas takes an amendment in (online or paper).
• How California handles amending a filed quarter.
• Whether, under IFTA's rules, interest on tax added by an amended report runs from the original due date. Not finding a rule is not the same as no interest being owed.

For any of these, the base jurisdiction is the one to ask.

One last thing

When anything here does not match what your base jurisdiction says, its word wins.

WheelsAndAxle is a preparation aid: it turns logged miles and fuel into a worksheet for review before filing.

Sources

• IFTA (iftach.org) — Articles of Agreement, 2025 edition (effective August 2025) — checked 2026-10-13
• IFTA (iftach.org) — Procedures Manual, 2025 edition (effective August 2025) — checked 2026-10-13
• IFTA (iftach.org) — Audit Manual (effective September 2024) — checked 2026-10-13
• Texas Comptroller — Fuels taxes frequently asked questions — page undated; checked 2026-10-13
• Texas Comptroller — Publication 96-336, IFTA Texas Guidebook — same wording in the July 2025 revision; checked 2026-10-13
• New York (tax.ny.gov) — Web File for IFTA — checked 2026-10-13
• New York (tax.ny.gov) — Form IFTA-100 (5/19) — checked 2026-10-13
• Illinois (tax.illinois.gov) — MFUT-15 instructions (R-01/26) — checked 2026-10-13
• Washington Department of Licensing — page on amending (changing) IFTA tax returns — page undated; checked 2026-10-13
• North Carolina Department of Revenue — IFTA amended returns, motor carrier seminar slides (2025) — checked 2026-10-13