IFTA (International Fuel Tax Agreement) is the system that lets trucking companies operating across state lines pay fuel taxes based on where they actually drove rather than where they bought fuel. If your trucking company is based in California, your base jurisdiction is California and you file through the California Department of Tax and Fee Administration (CDTFA).

Filing happens quarterly with these deadlines: Q1 (January through March) is due April 30, Q2 is due July 31, Q3 is due October 31, and Q4 is due January 31. You must file even if you had no operations during the quarter. Late filings carry a $50 penalty or 10% of the net tax due, whichever is greater, plus interest on any unpaid amounts. Those penalties add up fast across multiple quarters.

The core of IFTA reporting is two data sets tracked by jurisdiction. First, total miles driven in each state or province. Second, total gallons of fuel purchased in each state or province. From those numbers, you calculate your overall fleet fuel consumption rate (total miles divided by total gallons), then apply that rate to determine how much fuel you effectively “used” in each jurisdiction. You compare that against what you actually purchased there. If you bought more fuel than you used in a state, you get a credit. If you used more than you bought, you owe tax at that state’s rate.

The math itself isn’t complicated. The hard part is maintaining accurate records trip by trip throughout the quarter. Every trip needs the date, origin, destination, route, miles driven in each state, and fuel purchases with receipts showing gallons, price per gallon, and location. Missing or sloppy records turn filing day into a guessing game and make you vulnerable during audits. IFTA auditors can go back four years and they take record-keeping seriously.

Most freight and logistics companies use trucking management software like TruckingOffice, Rigbooks, or fleet management platforms that track this data automatically through ELD integrations or GPS. If you’re a smaller operation, a well-maintained spreadsheet organized by trip works too. What doesn’t work is trying to reconstruct three months of driving from memory when the deadline hits.

Keep fuel receipts for at least four years. Digital copies are acceptable but they need to show the date, seller name, number of gallons, fuel type, price per gallon, and the vehicle or fleet number. Credit card statements alone aren’t sufficient because they don’t show gallons purchased.

You can file through the CDTFA’s online portal, which walks you through entering miles and gallons by jurisdiction and calculates what you owe or what credit you’re due. Payment is submitted with the return.

Where bookkeeping ties into this is that IFTA payments need to be recorded properly in your books, fuel purchases need to be tracked and reconciled against your IFTA reports, and the credits or amounts owed affect your cash flow. If your books don’t reflect your IFTA activity accurately, your financial statements won’t tell you the true cost of operating in different lanes. Our Orange County small business bookkeeping services include working with trucking clients to make sure fuel tax reporting stays organized and on schedule throughout the quarter rather than becoming a last-minute scramble every 90 days.

The biggest mistake owner-operators make is treating IFTA as a once-a-quarter problem instead of building tracking into their daily routine. Log your miles and save your fuel receipts every single day. When the quarter ends, you’re just compiling data you already have instead of trying to piece it together from scattered records.