IFTA Audit Requirements: Practical Guide for Carriers and Small Fleets

Updated: August 25, 2026 at 1:01 PM

IFTA audit requirements generally require carriers to maintain records that support the distance traveled and fuel purchases reported on their IFTA returns. During an audit, the carrier’s base jurisdiction may review the records used to support those returns. These may include mileage records, trip reports, fuel receipts, bulk fuel records, GPS or vehicle-tracking data, and other supporting documents. IFTA records generally must be kept for four years from the return’s due date or filing date, whichever is later, although some circumstances can extend the retention period.

Key Takeaways

• An IFTA audit checks the distance and fuel records used to support the information reported on your IFTA returns.
• IFTA generally requires you to keep supporting records for four years from the return’s due date or filing date, whichever is later. Some circumstances can extend this period.
• Any IFTA licensee can be audited, including owner-operators and small fleets.
• GPS and vehicle-tracking records must contain specific information when used as IFTA distance records. The records must also be available in an acceptable electronic format.
• Missing or incomplete records can lead to audit adjustments, additional taxes, interest, penalties, or the loss of tax-paid fuel credits.

What Does an IFTA Audit Check?

An IFTA audit is a formal review conducted by your base jurisdiction to check whether the distance and fuel information reported on your IFTA returns is accurate. The auditor compares your returns with the records used to support your reported distance, fuel purchases, and tax-paid fuel credits.

IFTA audits go beyond the numbers on your quarterly returns. Auditors examine carrier-level records including individual vehicle distance records, trip sheets, GPS data, fuel receipts, and bulk fuel logs. Audit findings can result in additional tax, interest, penalties, or other consequences when reporting or recordkeeping problems are found.

This guide explains the IFTA audit requirements owner-operators and small fleets should understand, including recordkeeping, distance and fuel documentation, record retention, and what can happen when records are incomplete.

How IFTA Audit Selection Works

All licensees under the International Fuel Tax Agreement are subject to IFTA audits, regardless of fleet size. Even a single-truck owner-operator must maintain records that support IFTA compliance.

Under the IFTA Audit Manual effective January 1, 2026, base jurisdictions are required to complete audits averaging 3% per year of the IFTA accounts used for the program’s audit calculation, excluding new licensees. IFTA has considered proposals to reduce this requirement, but the current 2026 Audit Manual still establishes the 3% standard.

IFTA also sets requirements for the types of accounts included in each jurisdiction’s audit program, including high- and low-distance accounts. Individual jurisdictions may use additional selection methods, including random selection. This means accurate reporting does not eliminate the possibility of an audit.

IFTA and the International Registration Plan (IRP) can rely on some of the same distance records. Carriers subject to both programs should keep this overlap in mind. Maintaining consistent, well-supported distance data is therefore important for both IFTA fuel-tax reporting and IRP registration compliance.

IFTA Record Keeping Requirements

IFTA records must support the distance and fuel information reported on your returns. Your records should show where each qualified vehicle traveled, how far it traveled, and the fuel purchases used to support tax-paid fuel credits.

IFTA distance and mileage records generally need to include the following records and required data:

Distance record element	What the IFTA Procedures Manual requires
Trip dates	Beginning and ending dates of the trip
Origin and destination	Where the trip began and ended
Route of travel	The route traveled during the trip
Meter readings	Beginning and ending odometer, hubodometer, ECM, or similar readings
Total trip distance	Total distance traveled during the trip
Jurisdictional distance	Miles traveled in each of the applicable IFTA jurisdictions
Vehicle identification	Vehicle identification number or vehicle unit number

Carriers can use different types of source records, but those records must give the base jurisdiction enough information to verify reported distance and fuel. When needed for an efficient audit, the base jurisdiction may also require monthly fleet summaries.

Other supporting documents can help verify reported activity. These may include trip reports, detailed trip logs, dispatch records, driver logs, and bills of lading. These records can help support reported activity when reviewed with the required distance and fuel records.

Summaries alone are never enough. Auditors expect source documents that prove the summary numbers. Inadequate records can lead to audit adjustments or additional assessments. The base jurisdiction may also disallow tax-paid fuel credits that are not properly documented.

What Are the IFTA Requirements for GPS Records?

IFTA distance records must provide enough detail to document the fleet’s operations. Different requirements apply when a qualifying vehicle-tracking system is not used. Required information includes trip dates, origin and destination, route of travel, meter readings, total trip distance, jurisdictional distance, and vehicle identification.

An Electronic Logging Device (ELD) used for hours-of-service compliance does not automatically satisfy IFTA recordkeeping requirements. Automated systems reduce human error in record-keeping, but only if they meet the right standards.

Current GPS and vehicle tracking expectations for IFTA audits require:

• Location captured via latitude and longitude to at least four decimal places
• An ECM odometer reading for each system reading, or qualifying beginning and ending dashboard odometer or hubodometer readings when ECM odometer data is unavailable
• A record created and maintained at least every 10 minutes while the vehicle’s engine is on
• Exportable in usable electronic formats (XLS, XLSX, CSV, or delimited text)

Vehicle-tracking records produced under P540.200 must be accessible in an acceptable electronic format. Examples include XLS, XLSX, CSV, or a delimited text file. Static formats such as PDF, JPEG, PNG, or Word are not acceptable for this purpose. The system must also retain the original GPS location data rather than only summaries. This keeps the required data available to IFTA auditors throughout the applicable retention period.

Fuel Purchases and Bulk Fuel Records

Tax-paid credit for fuel purchases requires proper documentation. The records must document the transaction and identify the qualified motor vehicle that received the fuel. Retail fuel records must include required information such as the number of gallons or liters purchased, fuel type, purchaser information, and vehicle identification.

Required information on retail fuel receipts includes:

• Purchase date
• Seller’s name and address, or an acceptable identified vendor code
• Quantity of fuel purchased
• Type of fuel purchased
• Price per unit of volume or total purchase price
• Identification of the qualified motor vehicle fueled
• Name of the fuel purchaser

When the qualified motor vehicle is subject to a lease, IFTA permits the purchaser name to be either the lessor or lessee, provided a legal connection can be established between the purchaser named on the fuel documentation and the IFTA licensee.

IFTA permits supporting documentation such as a seller’s receipt, invoice, or transaction listing, a credit-card receipt, a third-party transaction listing, or an electronic or digital record of an original receipt or invoice, provided the applicable documentation requirements are satisfied.

Bulk fuel storage requires additional records. These include fuel-delivery receipts, quarterly inventory reconciliations, each tank’s capacity, and withdrawal records for every bulk tank at each location. Withdrawal records must identify the bulk-storage location and withdrawal date. They must also show the fuel quantity, fuel type, and vehicle or equipment receiving the fuel.

Tax-paid fuel credits may be disallowed when the required fuel documentation is missing or inadequate, which can increase the amount of tax assessed during an audit.

IFTA Record Retention Requirements

IFTA generally requires supporting records to be kept for four years. The period begins from the return’s due date or filing date, whichever is later. Carriers subject to the International Registration Plan may need to retain certain mileage records longer.

• IFTA generally requires applicable records to be retained for four years after the IFTA return for those operations was due or filed, whichever is later, plus any additional period covered by applicable waivers or jeopardy assessments.
• IRP generally requires records to be retained for the current registration period plus the three previous registration periods, with the exact retention period depending on the applicable registration periods and requirements.

Carriers subject to both programs should make sure their retention practices satisfy the applicable IFTA and IRP requirements, as well as any longer requirements imposed by their jurisdiction.

Records must be stored so they allow quick retrieval by unit, quarter, and jurisdiction. Electronic records are acceptable if they are legible, complete, and backed up against data loss.

How the IFTA Audit Process Works

The IFTA audit process generally begins when the licensee receives an audit notice from the base jurisdiction. Under the current IFTA Audit Manual, the licensee should be contacted at least 30 days before the audit and advised of the audit period, the types of records to be examined, and the proposed audit start date. An audit can begin sooner if the licensee agrees or the jurisdiction has just cause.

During the audit process, IFTA auditors review records supporting the carrier’s reported distance, fuel purchases, and average fuel-consumption calculations. Auditors may conduct evaluations of the internal controls related to accounting and record-keeping practices. Under the IFTA Audit Manual, auditors review the licensee’s distance and fuel accounting systems, compare summaries with filed tax returns, document internal controls, and test the reliability of those controls when appropriate. Auditors may use sampling to examine part of a carrier’s records rather than reviewing every transaction.

As part of the audit, the auditor also analyzes the tax returns under review for unusual trends or variances and documents relevant findings. If records for particular vehicles are impaired or missing, the auditor may use available evidence, including comparable operations and industry averages, when determining appropriate adjustments.

After the examination, the base jurisdiction prepares an audit report documenting its findings and any resulting adjustments. Because IFTA distributes fuel-tax obligations among member jurisdictions, audit findings can affect the tax amounts attributed to more than one jurisdiction. The report includes information about reported and audited distance, fuel, tax adjustments, penalties where applicable, and interest. A closing conference generally gives the licensee an opportunity to discuss the findings and any areas of noncompliance. If the licensee disagrees with the final results, appeal procedures depend on IFTA requirements and the rules of the base jurisdiction.

IFTA Audit Preparation and Audit Readiness

Good audit preparation starts long before an audit notice arrives. Ongoing audit readiness means keeping distance records, fuel data, trip reports, and supporting documents organized as part of normal record maintenance. This makes it easier to spot gaps, support your quarterly IFTA returns, and locate records if your base jurisdiction requests them during an audit.

Carriers using electronic vehicle-tracking systems should also understand whether their systems retain the detailed data required under IFTA, rather than assuming an ELD or mileage summary automatically satisfies IFTA recordkeeping requirements. Fuel documentation should likewise identify qualifying purchases and the vehicles receiving the fuel so that tax-paid credits can be supported.

Consistent recordkeeping supports ongoing IFTA compliance and makes it easier to identify discrepancies between source records and quarterly filings while the information is still readily available. Carriers that use the same distance information for IFTA and IRP should maintain records capable of supporting the requirements of both programs. If a carrier relies on an employee, outside service, or another reporting party to prepare its quarterly returns, the underlying source records should still support the distance and fuel information reported.

Get Help with IFTA Compliance and Quarterly Filing

FCCR provides IFTA registration and quarterly filing services for carriers that need assistance maintaining their IFTA accounts and reporting fuel-tax activity. Accurate quarterly reporting works hand in hand with the recordkeeping obligations described above because carriers remain responsible for maintaining records that support the information reported on their returns.

If you need help with ongoing IFTA reporting, learn more about FCCR’s IFTA & IRP Quarterly Filing Service. FCCR provides filing and compliance services but does not provide legal representation during IFTA audits.

IFTA Audit FAQ

Related Articles:

• IRP vs. IFTA: What’s the Difference and Which Do You Need?
• List of International Fuel Tax Agreement (IFTA) Websites
• Understanding Apportioned Plates in Vehicle Registration