Fleet Fuel Economy and IFTA Records

Does IFTA apply to your vehicles?

The International Fuel Tax Agreement lets a carrier license in one base jurisdiction and file one fuel tax return for its travel across all member jurisdictions. It covers a qualified motor vehicle, which the IFTA Articles of Agreement (R245) define as a motor vehicle used, designed or maintained to transport persons or property and that:

has two axles and a gross vehicle weight or registered gross vehicle weight over 26,000 pounds (11,797 kg); or
has three or more axles, regardless of weight; or
is used in combination, when the combination's gross vehicle weight or registered gross vehicle weight is over 26,000 pounds (11,797 kg).

Recreational vehicles are excluded. Once licensed, you receive an IFTA license and at least two decals per qualified vehicle. A copy of the license must be carried in each vehicle (R620), and the decals go on the exterior of both sides of the cab (R625). Decals are issued each year (R610).

Quarterly returns and due dates

Quarters follow the calendar: January to March, April to June, July to September and October to December (R254).
A return is due every quarter, even if a vehicle did not run or no taxable fuel was used (R930).
The due date is the last day of the month after the quarter ends. If that day falls on a weekend or legal holiday, the next business day counts (R960).
Annual filing is possible for a licensee whose travel outside the base jurisdiction totals under 5,000 miles (8,000 km) in 12 consecutive months, but only with the base jurisdiction's approval (R930).

Distance records an auditor will accept

The IFTA Procedures Manual (P540) lists what trip records should contain when they are kept by hand or by a system other than GPS tracking:

Element	Why it is there
Start and end dates of the trip	Places the trip in the right quarter
Origin and destination	Shows where the vehicle went
Route of travel	Supports the miles claimed in each jurisdiction
Start and end odometer, hubodometer or ECM reading	Proves the distance
Total trip distance	Reconciles to the readings
Distance in each jurisdiction	The basis of the tax split
VIN or unit number	Ties the trip to one vehicle

If distance comes from a GPS vehicle tracking system instead, P540 asks for a position at least every 10 minutes while the engine is on, with the date and time, latitude and longitude to four decimal places, the ECM odometer reading and the vehicle's VIN or unit number. The data must be available as a spreadsheet or delimited file; a PDF or image export is not acceptable.

Fuel receipts that earn tax-paid credit

Under P550, a retail fuel receipt, invoice or transaction listing must show the date, the seller's name and address (or an identified vendor code), the quantity and type of fuel, the price per volume or the total price, the vehicle the fuel went into, and the purchaser's name. A receipt that has been altered, shows erasures or is illegible is not accepted for credit unless you can show it is valid, and fuel put into a vehicle that is not a qualified motor vehicle earns no credit.

How long to keep them

Keep IFTA distance and fuel records for four years from the date the return was due or was filed, whichever is later, plus any period covered by a waiver or jeopardy assessment (P510). In an audit, the burden of proof is on the licensee (P520). Records can be kept in any format, as long as the auditor can audit them (P530).

Measuring fuel economy: the fill-to-fill method

Miles per gallon is only as good as the fills it is measured between. The reliable method:

Fill the tank to full and record the odometer.
At the next full fill, record the odometer and the gallons added.
Divide the miles driven between the two full fills by the gallons added at the second one.

Example: full at 120,400 miles, full again at 120,980 miles taking 92 gallons. 580 miles divided by 92 gallons is 6.3 mpg. A partial fill in between does not start a new measurement; its gallons add to the next full fill. If a fill has no odometer reading, do not estimate across it. Start again from the next full fill that has one.

Spotting fuel waste

Compare each vehicle with its own history, not with the fleet average. A tractor that normally returns 6.5 mpg and drops to 5.4 has a problem, whatever the fleet average says.
Idle time. Engine-on hours with no distance burn fuel and add engine wear. Telematics idle reports show which vehicles and drivers idle most.
Fills larger than the tank. More gallons than a vehicle's tank holds means fuel went somewhere else, or the fill was booked to the wrong unit.
Card use that does not match the vehicle. A purchase where the vehicle was not, the wrong fuel type, or two fills minutes apart are worth a question.
Odometers that go backwards. Usually a typing error, sometimes a swapped unit number. Either way it corrupts both the mpg and the IFTA miles.

One record for both jobs

Field	IFTA use	Fuel economy use
Vehicle (unit number or VIN)	Credit only for qualified vehicles	Economy per vehicle
Date and location of purchase	Quarter and jurisdiction of the fuel	Ties the fill to a trip
Gallons and fuel type	Tax-paid credit	The divisor in mpg
Odometer at the fill	Reconciles to trip distance	The miles in mpg
Price and total	Required on the receipt	Cost per mile
Full or partial fill	—	Decides where a measurement starts and ends

Never edit or delete a wrong fill. Correct it with a note of what was wrong, so the history an auditor reads is the history you actually had. Cargovate logs each fill-up against the vehicle, measures economy from one full tank to the next, and flags fills larger than the tank, economy far below the vehicle's own normal, and odometers that went backwards. Fuel costs also feed maintenance and running cost per mile.

IFTA rules here are from the Articles of Agreement and Procedures Manual in force in 2026. Your base jurisdiction administers your license and may add its own procedures; check with it before relying on a record format.