Every power only load starts with the same moment: you back under someone else's trailer. From that second until the drop is recorded, the trailer is your responsibility. The document that says so is the trailer interchange agreement, and the insurance that backs it is trailer interchange insurance for power only. This guide is the practical side: what the agreement asks of you, what coverage you need, and the checks to run at every hook. For the agreement itself in detail, see the trailer interchange agreement explained.
What the agreement covers
Different programs word their agreements differently, but nearly all of them cover the same ground:
- Possession. When the trailer becomes yours (at hook or gate-out) and when it stops (at drop or gate-in).
- Condition. How the trailer must be inspected at pickup and return, and what counts as damage.
- Liability. That you pay for damage, loss or theft while you have it, beyond normal wear.
- Return. Where and when you must return the trailer, and what happens if you are late.
- Insurance. What coverage you must carry and at what limits, often with the owner named on your certificate.
- Disputes. How damage claims and billing disagreements are settled.
For intermodal containers and chassis, most equipment owners and carriers use one industry agreement, the UIIA, run by the Intermodal Association of North America. Broker and shipper power only programs usually have their own versions with similar terms.
The insurance you need
Your normal policies don't cover a trailer you don't own. Auto liability covers damage you cause to others; cargo covers the freight. Neither pays to fix the trailer if you clip a pole backing into a door.
That gap is filled by trailer interchange coverage, sometimes sold as non-owned trailer physical damage. It pays for covered damage to a trailer in your care under an interchange agreement. Programs set minimum limits, and the limit has to be on your certificate before they approve you.
A few practical points:
- Ask each program for its exact requirement before you apply. Limits vary.
- Make sure the certificate lists the coverage by name. Programs reject certificates that don't show it.
- Know your deductible. Small damage often costs less than the deductible, and you pay it directly.
- If you pull intermodal equipment, check the UIIA's insurance requirements too; they are separate from broker programs.
This is general information, not insurance advice. Your agent can tell you what your policy actually covers.
The hook checklist
Run this at every trailer, every time. Tick it on your phone or print it for the cab. Ten checks take a few minutes and save most damage disputes.
HOOK CHECKLIST / POWER ONLY
0/10
Tick each one at the trailer.
For a full walk-around beyond these ten, see our truck and trailer inspection guide.
What we check before booking
Before a power only load ever reaches you, our desk checks the parts that go wrong most often:
- That you are approved for the program and the agreement is signed.
- That your certificate matches the program's interchange requirement.
- Where the trailer is and how long the yard check-in usually takes.
- Return terms for the trailer, so you aren't charged for a late drop.
- Who pays to move empties, so repositioning isn't free work.
Then the rate con comes to you, with the trailer and yard details on it, and you decide.
Who pays when: common scenarios
Most interchange disputes fit one of a few patterns. The details depend on your agreement, but this is how they usually play out.
| Scenario | Usually responsible | What protects you |
|---|---|---|
| Damage that was there before you hooked | The owner or the last carrier | Photos and notes at the hook |
| You clip something backing into a door | You, the carrier in possession | Trailer interchange coverage |
| Flat tire or worn brakes found at hook | The owner, if noted before you leave | A note on the gate paperwork |
| Receiver damages the trailer while unloading | Disputed; often the carrier first | A damage note on the delivery receipt |
| Trailer returned late | You, under the return terms | Knowing the return deadline before you book |
The pattern is the same every time: the carrier who had the trailer last, with no paperwork saying otherwise, ends up holding the bill. A few minutes of photos and notes at each end is the cheapest insurance in power only.
When something goes wrong
Even with every check done, things happen: a tire blows, a door gets damaged at a dock, a seal turns out to be wrong. When it does:
- Photograph it immediately, with time and location.
- Tell the program or broker before you move on, and tell us.
- Get the issue written on the delivery paperwork.
- Keep your hook photos with the load record.
Most disputes come down to one question: what condition was the trailer in when you took it? Good hook photos answer that. Keep them for at least as long as the program can bill you for damage, which the agreement spells out, and store them with the load so you can find them months later. A simple folder per load, named with the date and trailer number, is enough.
Ready to run power only with someone handling the paperwork? See our power only dispatch guide for how the loads get strung together.
Questions carriers ask
01What is a trailer interchange agreement?
A contract between the trailer's owner and the carrier pulling it. It says who is responsible for the trailer while you have it, how it must be inspected, how damage is handled and paid for, how and when it is returned, and what insurance you must carry. Intermodal equipment uses the industry-standard UIIA.
02Do I need trailer interchange insurance for power only?
Almost always. Programs and equipment owners require trailer interchange or non-owned trailer physical damage coverage so damage to their trailer is covered while you have it. Your auto liability and cargo policies don't cover the trailer itself. Each program sets its own minimum limit.
03What should I check before hooking a pool trailer?
The agreement and your insurance on file, the trailer ID and seal number against the paperwork, photos of all sides, tires, lights, doors, registration and any existing damage noted on the paperwork. Do it every time, even at a yard you know well.
04Who pays if a pool trailer is damaged?
Under most interchange agreements, the carrier who had the trailer when the damage happened. That is why the hook photos and damage notes matter: they separate damage you caused from damage that was already there. Your trailer interchange coverage pays for covered damage, minus your deductible.
SOURCES
SOURCE: Primary sources listed above, checked on the dates shown.