The Short Version:
A trip permit satisfies the registration requirement (IRP) — it proves your truck is authorized to travel in a state. A fuel permit satisfies the fuel tax requirement (IFTA) — it proves you can legally buy and consume fuel in a state. Both cover the same vehicles, both are required when you lack the corresponding permanent credentials, and both are often ordered together for the same trip.
The Two Compliance Systems
Interstate commercial trucking in the U.S. is governed by two parallel agreements:
- International Registration Plan (IRP) — coordinates vehicle registration so carriers pay apportioned fees based on miles traveled in each state. This is what a trip permit replaces when you don't have IRP plates.
- International Fuel Tax Agreement (IFTA) — coordinates fuel tax reporting so carriers pay fuel taxes to the states where they actually consumed the fuel, not just where they bought it. This is what a fuel permit replaces when you don't have IFTA credentials.
Carriers with full IRP and IFTA credentials only need these temporary permits for specific situations (like adding a new vehicle before the registration is processed). Everyone else needs them for every out-of-state trip.
Side-by-Side Comparison
| Trip Permit | Fuel Permit | |
|---|---|---|
| What it covers | Vehicle registration (IRP) | Fuel tax compliance (IFTA) |
| Legal basis | International Registration Plan | International Fuel Tax Agreement |
| Who requires it | Every state you enter | Every state you enter |
| Vehicles required | 2-axle >26,000 lbs; or 3+ axles interstate | 2-axle >26,000 lbs; or 3+ axles interstate |
| Permanent alternative | IRP apportioned plate | IFTA license & decals |
| Duration | Usually 72 hours (varies by state) | Usually 72 hours (varies by state) |
| Cost range | $40–$80 per state (typical) | $25–$60 per state (typical) |
| Issued by | State DMV / motor vehicle authority | State revenue / tax authority |
When You Need Both
In most situations, if you need one, you need the other. The thresholds are identical — two axles over 26,000 lbs GVW, or three or more axles traveling interstate. So when a truck hits those numbers without IRP or IFTA credentials:
- You need a trip permit to be legally registered in each state you enter
- You need a fuel permit to legally purchase or consume taxable fuel in each state
When you call Custom Permits, we'll figure out exactly which permits you need for your specific route and vehicle setup. Most carriers ordering temporary permits need both — we'll bundle them together and have everything ready fast.
When You Might Only Need One
There are edge cases where a carrier has one type of credential but not the other:
- IFTA without IRP: Rare, but possible for a carrier registered in a base state that processes IFTA separately from IRP. They'd need trip permits but not fuel permits.
- IRP without IFTA: Also rare. A carrier with an IRP apportioned plate but no IFTA license would need fuel permits but not trip permits.
- New vehicle added to fleet: If you're adding a truck before its IRP registration processes, you might need a trip permit even though your fleet has IFTA credentials.
The California Exception
California requires its own trip permit from all commercial vehicles entering the state, regardless of weight or axle configuration. California is not part of IFTA for certain vehicle classes the same way other states are, and it uses its own system (the California Interstate Highway permit process).
Bottom line: if you're going to California, call us. The requirements are more complex than most states.
The Mileage/Weight-Distance Permit Add-On
Some states have a third requirement on top of IRP and IFTA: a separate mileage permit (sometimes called a weight-distance permit). These states include:
- New York — NY HUT (Highway Use Tax). Read our full NY HUT guide.
- Kentucky — KYU (Kentucky Weight Distance Tax). Read our full KYU guide.
- New Mexico — Weight Distance Tax
- Oregon — Oregon Weight-Mile Tax
These are entirely separate from trip permits and fuel permits. If your route passes through any of those states, budget for the additional permit fees.
How the Permanent Alternatives Work
If you're running interstate regularly, it makes financial sense to get the permanent credentials:
- IRP registration: Register in your base state. Pay apportioned registration fees based on the percentage of miles you drive in each jurisdiction. Get one plate that's valid everywhere. You no longer need trip permits.
- IFTA license: Register for IFTA in your base state. File quarterly fuel tax returns. You no longer need fuel permits, and you may even get refunds for fuel-heavy states.
The break-even point varies, but carriers making more than 4–6 cross-state trips per year typically save money with permanent credentials over buying per-trip permits.
Frequently Asked Questions
Do I need to buy a trip permit AND a fuel permit for every state I pass through?
Yes — if you don't have IRP and IFTA credentials. You need both permits for every state your truck enters, including states you're just passing through.
Is a fuel permit the same as an IFTA decal?
No. An IFTA decal is the permanent credential issued when you register for IFTA. A fuel permit is a temporary, trip-specific substitute for carriers who don't have IFTA.
Can I drive through a state without buying a fuel permit if I don't buy any fuel there?
The permit requirement isn't based on whether you buy fuel — it's based on entering the state with a qualifying vehicle. Even if you don't stop to fuel up, you still need the permit.
How long does it take to get both permits?
With Custom Permits, both trip and fuel permits are typically ready in under an hour. We handle the state portals for all 50 states.
Need Trip & Fuel Permits for Your Next Run?
We'll sort out exactly what you need for your route and have everything ready fast. Custom Permits has been doing this since 1977.