The International Registration Plan (IRP) is a reciprocal agreement among the 48 contiguous US states, Washington DC, and 10 Canadian provinces, governed by the IRP Plan and administered by AAMVA. Carriers operating qualified vehicles — 26,001+ lbs gross weight or 3+ axles regardless of weight — in two or more jurisdictions register once in their base state and receive a single “apportioned” license plate plus a cab card listing every jurisdiction the vehicle is authorized to operate in. The annual fee is split (apportioned) among all listed jurisdictions based on the percentage of total mileage the vehicle ran in each.
Who must register
The IRP applies to any “apportionable vehicle” under Plan Article II:
- Power unit with a registered or actual gross weight in excess of 26,000 lbs
- Power unit with three or more axles regardless of weight
- Combination vehicle that exceeds 26,000 lbs combined
Trailers themselves are not apportioned in most base jurisdictions; they receive a permanent or annual trailer plate from the home state and operate freely under reciprocity. Drive-away/tow-away operations have their own registration class. Vehicles operating exclusively in one state do not need IRP — the moment any qualified vehicle crosses a state line for hire (or for the carrier’s own benefit), it must be on apportioned plates.
Trip permits (typically $20–$50 per state per trip) can substitute for IRP plates on infrequent cross-border movement, but the math doesn’t work for any operation entering more than ~5 states per year.
Base jurisdiction selection
Same definition as IFTA: the state where the carrier maintains operational records, has a vehicle registered, and accrues mileage. Many carriers use the same base for IRP and IFTA, though the Plan permits separate base jurisdictions.
Picking the right base matters. Some states have sharply lower fee schedules for the “base” portion of the apportioned bill. Indiana, Oklahoma, and South Dakota are commonly cited low-cost base jurisdictions. The flip side: if you actually run mostly in higher-tax states, your apportioned fee for those states is unaffected by the base state — the math evens out.
Most carriers base where their books and dispatch actually live. The administrative friction of basing in a state where you don’t physically operate usually outweighs the fee savings.
How the apportionment math works
The annual IRP fee is the sum of jurisdiction fees, each multiplied by the percentage of total mileage you ran in that jurisdiction. The base state runs the calculation when you apply.
Worked example for a single Class-8 tractor declared at 80,000 lbs running 100,000 total miles distributed across Indiana (40%), Illinois (25%), Ohio (20%), Pennsylvania (15%):
- Indiana 80K-lb annual fee: $1,650 × 40% = $660
- Illinois 80K-lb annual fee: $2,790 × 25% = $698
- Ohio 80K-lb annual fee: $1,260 × 20% = $252
- Pennsylvania 80K-lb annual fee: $1,720 × 15% = $258
- Total apportioned fee: ~$1,868
Numbers vary year over year and by vehicle class. New carriers without prior mileage records use estimated mileage; the next renewal reconciles to actual operating data. An IRP audit can come up to 4 years out and assess back fees if the estimate was understated.
The cab card and why it matters
The cab card is the document the IRP issues with the apportioned plate. It lists:
- The carrier name and base state
- The vehicle’s VIN and weight class
- Every jurisdiction the vehicle is authorized to operate in
- The apportioned weight in each (sometimes “same-as-registered” or a higher declared weight for a specific state)
The cab card must be in the vehicle while operating. State weigh stations and roadside enforcement use the cab card to verify the vehicle is authorized in their jurisdiction. A missing cab card is a citation but rarely an out-of-service order. A vehicle running in a jurisdiction not listed on the cab card faces unregistered-operation penalties that scale by GVW.
The annual application — what to gather
IRP applications run on a state-set schedule. Most states use a calendar-year cycle (renewal due December 31), but several use a March or July cycle. The renewal application requires:
- Current MCS-150 on file (no MCS-150, no IRP renewal in most states)
- Prior 12 months of mileage by jurisdiction (the “reporting period”)
- VIN and title for each vehicle
- UCR paid for the current year
- Stamped Schedule 1 from Form 2290 for any vehicle 55,000+ lbs
- Insurance proof matching FMCSA financial responsibility minimums
- State-specific items (e.g., NY HUT, KY KYU certificate of registration)
Run the state permit calculator to see which state-specific permits stack on top of IRP.
2290 Schedule 1 is the renewal showstopper
The single most-common IRP renewal stall: a missing or out-of-date stamped Schedule 1 from Form 2290. Most states block IRP renewal until the IRS-stamped document is on file. File 2290 in early August so it lands well before any IRP cycle. Fast2290Filing e-files and returns the Schedule 1 same business day.
Adding and removing vehicles mid-year
Carriers can add vehicles to an existing IRP account at any time during the registration year. The base state pro-rates the apportioned fee for the remaining months and issues a supplemental cab card. Removing a vehicle (sale or retirement) requires returning the plate and cab card to the base state for credit toward future renewals.
Transferring an IRP plate from one vehicle to another in the same fleet (a tractor swap) is straightforward and usually carries a $5–$50 transfer fee. Transferring an IRP plate from one carrier to another is generally not permitted; the new carrier opens their own IRP account.
IRP audits — what triggers them, what they look for
Each IRP base jurisdiction is required by Plan Article XV to audit at least 3% of its registered fleet annually. Auditors review the reported mileage and fuel records against ELD output, fuel receipts, and IFTA returns. Common findings:
- Unrecorded miles in a jurisdiction the carrier didn’t list
- Discrepancy between IRP-reported miles and IFTA-reported miles for the same period
- Trip permits used in lieu of plates without retaining permits as records
- Missing or non-compliant individual vehicle mileage records (IVMRs)
Failed audits assess back fees plus an additional penalty (often 25%) plus interest. Records must be retained for 4 years from the registration year. The audit window is up to 4 years.
Reciprocity, trip permits, and edge cases
The IRP Plan provides full registration reciprocity within member jurisdictions for any vehicle properly displaying an apportioned plate listed on a current cab card. Several edge cases:
- Trip permits. A non-IRP-registered vehicle can enter a state on a one-time trip permit (typically $20–$50). Costs add up fast for any vehicle that crosses borders more than ~5 times annually.
- Mexico and outside-IRP areas. The IRP only covers the 48 contiguous US states, DC, and 10 Canadian provinces. Operations in Alaska, Hawaii, Mexico, or Mexican Border zone require separate registrations under each jurisdiction’s rules.
- Trailers. IRP does not generally apportion trailer registrations. Most states issue a permanent or annual trailer plate that operates under reciprocity.
- Drive-away/tow-away. Vehicles being moved as cargo (a tractor moving another tractor as freight, or a tractor being driven from a manufacturer to a dealer) use a different registration class. Drive-away operators have unique IRP treatment.
- Buses. Inter-jurisdictional bus operators register under IRP if they cross state lines. Reciprocity for charter buses varies by state.
Estimated mileage vs actual mileage reconciliation
A new carrier without prior IRP history files using estimated mileage by jurisdiction. Most base states have minimum-mileage tables that establish a floor in each jurisdiction the carrier declares. The first year’s fees calculate on this estimate.
At the Year 2 renewal, the actual mileage from the prior year replaces the estimate. Carriers who underestimate face a back-fee assessment in any state where actual mileage exceeded the estimate by a material amount. Conversely, overestimates do not refund — they just establish a higher cost basis going forward.
The takeaway: estimate realistically, not minimally. A 30%-low estimate that the carrier corrects at Year 2 results in 30% back fees plus a routine penalty in many base states. The math rarely benefits the carrier.