Table of Content
- Who runs an IFTA audit, and what is it checking?
- What triggers an IFTA audit?
- Be Ready Before the Auditor Calls
- What happens after you get the audit notice?
- Which records close an IFTA audit?
- What does the auditor compare?
- What happens if your records are not good enough?
- How do you get ready before the letter arrives?
- Where does a back office fit in?
- Frequently asked questions
Short answer
An IFTA audit is run by your base state on behalf of every IFTA jurisdiction, and the burden of proof is on you. Every base jurisdiction has to audit a share of its accounts each year, with set minimums for the highest-mileage and lowest-mileage carriers. What closes the audit is not an explanation but records: trip or GPS data with miles by state, fuel receipts that carry every required field, and monthly summaries that tie both to your quarterly returns. Without adequate records, the rules let the auditor assume 4.00 MPG for the whole fleet.
Who runs an IFTA audit, and what is it checking?
Under the International Fuel Tax Agreement you file one quarterly return with your base jurisdiction, and that jurisdiction splits the tax among every state and province you drove in. The audit follows the same logic. Section R1310 of the IFTA Articles of Agreement says the base jurisdiction shall audit its licensees on behalf of all member jurisdictions, and other jurisdictions may also audit you at their own expense.
The audit checks two numbers per quarter: the miles you drove in each jurisdiction and the fuel you put in the truck. Everything else follows from those. Two rules shape how it goes:
- The burden is yours. Section P520 of the IFTA Procedures Manual reads: “In an IFTA audit, the burden of proof is on the licensee.”
- It covers a full year. The IFTA Audit Manual requires counted audits to cover all returns for a license year or at least four consecutive quarters.
If you need a refresher on the return itself, start with our guide to the IFTA report.
What triggers an IFTA audit?
No jurisdiction publishes its selection model, so be wary of any list that claims to know exactly why a carrier was picked. What the IFTA rules do publish is the minimum every base jurisdiction has to meet. That alone tells you a lot about who gets audited.
- A yearly quota. Section A250 of the Audit Manual requires each base jurisdiction to complete audits of an average of 3 percent per year of its IFTA accounts, not counting new licensees.
- The highest-mileage quarter. Under A260, at least 25 percent of the required audits must involve high-distance accounts, defined as the 25 percent of the previous year’s licensees with the most miles reported.
- The lowest-mileage quarter. At least 15 percent must involve low-distance accounts, the 25 percent of licensees with the fewest miles.
- Records reviews. A jurisdiction may substitute three records reviews for one audit, for up to 25 percent of its requirement. A records review is a lighter check of your books that can come before or instead of a full audit.
So a busy owner-operator running heavy interstate miles sits in exactly the group the rules require jurisdictions to cover. A part-time truck with very few miles sits in the other required group.
Beyond the quota, the return itself is the first thing an auditor reads. Section A310 requires the auditor to analyze the returns under audit and “note unusual trends or variances”. Fuel economy that jumps between quarters, miles that do not fit your lanes, or late and amended returns are the kind of pattern that stands out. Our post on what your dispatcher handles for IFTA and what stays on you covers those day-to-day risks.
A missed return is a separate path. Section R1210 of the Articles lets the base jurisdiction assess your tax on the best information available to it if you fail to file, fail to make records available upon written request, or fail to keep records from which your true liability can be determined.
What happens after you get the audit notice?
The Audit Manual sets the steps every base jurisdiction follows. Your state’s own procedures fill in the details, but the order looks like this:
| Step | What the rules say | What it means for you |
|---|---|---|
| Notice (A420) | You should be contacted at least 30 days before the audit and told the audit period, the type of records and the proposed start date. | Use the 30 days to pull every quarter in the audit period together. |
| Records request (A430) | The auditor must request the records needed for the selected audit period. | Answer the list item by item, in a format the auditor can work with. |
| Opening conference (A440) | A documented meeting on your operations, your distance and fuel accounting system, the records and the sample period. | Explain how your miles and fuel are recorded. This is where the auditor learns your system. |
| Testing (A320, A330) | The auditor tests your internal controls and decides whether sampling is appropriate based on how well they work. Unless a situation dictates otherwise, the audit is done on a sample of periods. | A clear, consistent system for miles and fuel is what the auditor is testing. |
| Closing conference (A450) | A documented meeting on any non-compliance and on required improvements. | Ask what changes they want in your records going forward. |
| Audit report (A460) | A written report with a narrative and a billing summary, sent to you and to every affected jurisdiction. | Check the adjustments line by line against your own files. |
| Appeal (R1390) | You get at least 30 calendar days from notice of the findings to file a written appeal. | Mark the date the day the report arrives. |
Section A420 also allows the audit to start inside the 30 days if you agree or for just cause. If your records are kept outside your base state and the auditors travel to them, section P510 lets the base jurisdiction charge you its reasonable per diem and travel costs.
Which records close an IFTA audit?
The standard is set by section P530 of the Procedures Manual. Records must be adequate to let the base jurisdiction verify the distances traveled and the fuel purchased, and adequacy is judged on two tests: sufficiency (enough records to document the fleet’s operations) and appropriateness (records that hold the information an auditor needs). The manual then lists the elements that make records adequate.
| Record | What it must show | Rule |
|---|---|---|
| Trip sheets or other distance records | Trip dates, origin and destination, route, beginning and ending odometer or ECM readings, total trip distance, distance in each jurisdiction, unit number or VIN | P540.100 |
| GPS or ELD tracking data | A reading at least every 10 minutes while the engine is on, with date and time, latitude and longitude to 4 decimal places, ECM odometer and unit number, in a spreadsheet format such as XLS, XLSX or CSV | P540.200 |
| Retail fuel receipts | Date, seller name and address, quantity, fuel type, price, the truck fueled and the purchaser’s name | P550.300 |
| Bulk fuel records, if you have a tank | Delivery receipts, quarterly inventory reconciliations per tank, tank capacity, withdrawal records | P550.400 |
| Monthly summaries | Miles and fuel for each vehicle, in total and by jurisdiction, matching the quarterly return | P560 |
Three details trip carriers up:
- Screenshots do not count. P540.200 says tracking data in a static image such as PDF, JPEG, PNG or Word is not acceptable. Export the raw file from your ELD or GPS provider every quarter, while you still have access to it.
- Bad receipts lose credit. Under P550.200, a receipt that has been altered, shows erasures or is illegible will not be accepted for tax-paid credit unless you can show it is valid.
- Four years, not one. P510 requires you to keep records for four years following the date the return was due or was filed, whichever is later. Selling the truck or switching ELD providers does not end that clock.
P530 also says records may be produced through any means and kept in any format, as long as the auditor can audit them. Records the auditor cannot work with count as not made available.
What does the auditor compare?
Section A320 tells the auditor to compare the distance and fuel summaries you provide with your tax returns and to document any differences. From there:
- Summaries versus returns. If they do not match, A330 requires the auditor to find out why, then decide whether to project the sample results from your summaries or from your returns.
- Miles you cannot place. If the auditor finds unreported distance and cannot tell where it was driven, A340 says it is allocated using a rational and unbiased approach. You lose the chance to place those miles yourself.
- Fuel economy. When the fleet’s records are adequate overall, A350 lets the base jurisdiction adjust your reported MPG. For specific trucks whose records are substantially impaired or missing, it can use your prior history, similar carriers, other trucks in your fleet, industry averages or third-party fuel records.
- Total fuel. A360 says reported total fuel is reduced only with clear proof from your records, and a missing receipt alone does not cut your total fuel.
What happens if your records are not good enough?
This is where an IFTA audit gets expensive, and the rules are specific.
- An assumed 4.00 MPG. If your records for the fleet as a whole fail the P530 adequacy test, or you produce no records after a written demand, P570.100 requires the base jurisdiction to impose an additional assessment by reducing your reported fleet MPG to 4.00 or by reducing your reported fuel economy by 20%. Lower MPG means more taxable fuel in every state you drove through.
- No credit for fuel tax you already paid. P550.220 says credit for tax paid on a retail purchase is allowed only if you produce a receipt, invoice, credit card receipt or transaction listing for it. Without that document, the tax you paid at the pump in that state is not credited on the audit.
- An assessment presumed correct. Under R1210, a best-information assessment is presumed correct, and you carry the burden of proving it erroneous or excessive by a fair preponderance of evidence. Before assessing on missing records, the jurisdiction must give you a written request with 30 days to provide them.
- Penalty and interest. R1220 allows a penalty of $50.00 or 10 percent of delinquent taxes, whichever is greater. R1230 sets interest for U.S.-based fleets at two percentage points above the IRS underpayment rate, accruing monthly, and a full month’s interest accrues for any part of a month the tax stays unpaid.
P570.200 adds that the base jurisdiction keeps the power, for cause, to run a best information available audit and to suspend, revoke or cancel the license.
How do you get ready before the letter arrives?
Every item below is something an auditor can ask for. Doing it each quarter is routine work. Rebuilding it years later from memory and old statements is far harder.
- Export tracking data each quarter in CSV or XLS from your ELD or GPS provider, and store it with that quarter’s return.
- Match fuel to the fuel card statement. Every gallon on the return should trace to a receipt or a transaction listing with the truck identified.
- Build a monthly summary per truck showing miles and gallons by state. It is the bridge between raw data and the return, and P560 lets the auditor demand it.
- Check your MPG every quarter. If it moves sharply, write down why (new truck, different lanes, idling season) while you still remember.
- Fix mistakes with an amended return rather than waiting for the auditor to find them.
- Keep four years of everything, in a format you can hand over without the original software.
For the basics of who must file and how decals work, see what IFTA is and why it matters.
Where does a back office fit in?
Logity Dispatch’s IFTA service handles the quarterly side of this: collection and verification of mileage, fuel purchases and jurisdiction data, calculation of tax and credits for each state and province, audit-ready reports every quarter, and secure digital storage of all filings, with a personal IFTA specialist and no long-term contracts. When an audit is coming, our safety and DOT compliance service prepares and organizes your compliance files and supports you through DOT, FMCSA, IRP and IFTA audits. To start, you send your MC authority number, insurance and W9, and setup is free.
Frequently asked questions
How far back can an IFTA audit go?
You must keep IFTA records for four years after the return was due or filed, whichever is later. Section P510 of the IFTA Procedures Manual says that, unless you grant a waiver, no deficiency assessment or refund can be made for a period for which you are no longer required to keep records. The four years are extended by any period covered by a waiver or a jeopardy assessment.
How much notice do you get before an IFTA audit?
Section A420 of the IFTA Audit Manual says the licensee should be contacted at least 30 days before the audit and told the audit period, the records to be audited and the proposed start date. The audit can start sooner if you agree or for just cause.
What MPG does the auditor use if my records are missing?
If your fleet’s records are inadequate as a whole, or you produce none after a written demand, section P570 of the IFTA Procedures Manual requires an assessment that reduces your reported MPG to 4.00 or cuts your reported fuel economy by 20%.
Can I appeal an IFTA audit?
Yes. Section R1390 of the IFTA Articles of Agreement gives you at least 30 calendar days from the date you are notified of the findings to file a written appeal with your base jurisdiction. The appeal follows that jurisdiction’s own administrative procedures.
