Semi trailer insurance: who covers the trailer you pull
Your semi truck policy can protect the public from the trailer behind you and still pay nothing when that trailer is damaged. Which coverage answers depends on who owns the trailer and what you signed to pull it.
Written by Rigo Diaz
Trailer coverage in numbers
Semi trailer insurance comes in two parts. Liability for a trailer generally follows the tractor pulling it, so your auto policy usually answers for a trailer hooked to your covered truck. Damage to the trailer itself takes physical damage for trailers you own, and trailer interchange or hired auto physical damage for trailers you don't.
When a carrier asks me whether its semi truck insurance covers the trailer, I answer with two questions: whose trailer is it, and what did you sign to pull it? Those two answers decide which policy pays.
I spent more than six years in risk management before I founded Simplex, and I have led it for more than 25 years since. This guide walks through each kind of trailer a carrier pulls, owned, interchanged, rented, power-only, and intermodal, and the coverage each one needs.
The full briefing, read aloud
7 chapters. Select one to jump to it.
Generated with AI text-to-speech from this article's key insights, in order, rather than reading it word for word. Chapter times come from a transcript of the audio. The article itself was written and reviewed by Rigo Diaz.
Key takeaways
Liability follows the tractor
Under ISO's standard motor carrier form, a trailer's liability coverage runs on the same basis as the covered power unit pulling it.
A trailer you don't own is covered only while attached
The owned-auto and listed-auto symbols most fleets use pick up non-owned trailers for liability only while they're hooked to your power unit.
Someone else's trailer needs its own coverage
Trailer interchange pays what you owe under a written interchange agreement; a rented trailer needs hired auto physical damage.
Your own trailer can lose coverage when it leaves
The standard form excludes physical damage while your trailer is in another carrier's possession under an interchange, unless you add symbol 70.
Contracts set the real limits
The UIIA requires $1 million in auto liability, and Amazon Relay asks for $50,000 of trailer replacement coverage.
In this articleContents
Does semi truck and trailer insurance cover the trailer?
For liability, usually yes; for damage to the trailer itself, only if you bought the right coverage. Liability pays for injury and damage you cause to others, and for a trailer it rides with the tractor. Damage to the trailer depends on who owns it and on the agreement you pull it under.
Most trucking policies use ISO's Motor Carrier Coverage Form or an insurer's version of it. IRMI describes the motor carrier policy as one form for auto liability, trailer interchange, and physical damage, for for-hire and private carriers alike. The table follows that form's 2013 edition.
| Trailer | Liability while hooked to your tractor | Damage to the trailer |
|---|---|---|
| Your own trailer, covered on your policy | Your auto liability, on the same basis as the tractor | Your physical damage coverage, if you bought it for that trailer |
| Your trailer, pulled by another carrier under an interchange | The other carrier's coverage first; yours is excess | Excluded, unless your physical damage carries symbol 70 |
| A trailer or container you don't own, under a written interchange agreement | Your auto liability, while it's attached to your covered tractor | Trailer interchange coverage (symbol 69) |
| A trailer you rent or lease without a driver | Hired autos liability (symbol 68), if your policy has it | Hired auto physical damage, if your policy has it |
| A customer's trailer on a power-only load | Your auto liability, while it's attached | Whatever the customer's agreement makes you responsible for |
How does liability work for the trailer behind your tractor?
It follows the power unit. Under the Motor Carrier Coverage Form, a covered trailer connected to a power unit is covered for liability on the same basis as that power unit: primary if the tractor's coverage is primary, and excess if the tractor isn't a covered auto on your policy.
Non-owned trailers count only while attached
Symbols 62, 64, and 67 cover trailers you don't own for liability only while they're connected or attached to your power unit. A customer's trailer you drop in your yard falls outside those symbols until you hook it again. Our guide to commercial auto symbols explains each one.
One limit per accident, however many units
The form pays no more than your liability limit for any one accident, regardless of the number of covered autos or vehicles involved. For-hire carriers hauling general freight across state lines need at least $750,000 for vehicles rated 10,001 pounds or more under 49 CFR 387.9, and $1 million or $5 million for hazardous materials. Our semi truck insurance page covers every limit and the MCS-90 endorsement.
Interchange between carriers takes a written agreement
When authorized for-hire carriers swap equipment, 49 CFR 376.31 requires a signed written agreement that describes the equipment, the points of interchange, how it will be used, and the compensation. Trailer-only interchanges skip the operating statement that must otherwise ride with the vehicle. That agreement is also the paper your trailer interchange coverage reads.
What covers damage to a trailer you don't own?
Trailer interchange coverage, when you hold the trailer under a written interchange agreement, or hired auto physical damage, when you rent it. IRMI explains that trailer interchange insurance covers your legal liability for damage to other people's trailers, because an interchange agreement makes the carrier in possession responsible, attached or not.
How trailer interchange coverage works
- The agreement is the trigger. Symbol 69 covers trailers you don't own while in your possession under a written trailer or equipment interchange agreement in which you assume liability for them.
- It pays what you owe. Comprehensive, specified causes of loss, or collision, for the trailer and its equipment, with a defense if the owner sues.
- It has its own limit. The most it pays is the least of actual cash value, repair cost, or the limit on your declarations, minus your deductible.
- It is primary, and for this coverage only, a container counts as a trailer.
- It won't pay loss of use. If the agreement bills you for the days a damaged trailer sits, that charge is yours.
Rented and leased trailers
A trailer you rent without a driver is a hired auto. Symbol 68 next to liability covers it, and symbol 68 next to physical damage, called hired auto physical damage, treats it as if you owned it. That coverage also pays loss of use under a written rental contract, but the 2013 form caps it at $20 a day and $600 in total.
Check whether your paper is a rental contract or an interchange agreement, because each one triggers a different coverage.
Power-only loads
On a power-only load you pull a shipper's or broker's trailer, so the customer's terms decide what you owe if it's damaged. Amazon Relay, for example, requires $1 million in auto liability, including $50,000 of trailer replacement coverage. Our Amazon Relay requirements guide covers the power-only equipment rules.
How do you insure a semi trailer you own?
List it for physical damage, the same way as the tractor, because liability never pays to repair your own trailer. The form offers comprehensive, specified causes of loss, or collision, and pays the lesser of actual cash value or the repair cost, minus your deductible. It excludes:
- Wear and tear, freezing, and mechanical or electrical breakdown
- Blowouts, punctures, and other road damage to tires, unless the whole trailer is stolen
- Your trailer while it's in anyone else's possession under a written trailer interchange agreement, unless symbol 70 is entered next to that physical damage coverage
The interchange exclusion doesn't apply to a loss payee, such as your lender. But if the insurer pays the lender, you must pay the insurer back, so interchanging a financed trailer without symbol 70 can turn a total loss into a debt. Our physical damage insurance page covers valuation and deductibles.
Leased on with your own trailer
If you lease your tractor and trailer to a carrier, 49 CFR 376.12 gives the carrier exclusive possession, control, and use of the equipment for the lease, and requires the lease to say who provides any insurance beyond the carrier's public liability. Physical damage on your trailer is one of those lines, so find it in the lease before you assume anyone carries it. For driving off dispatch, see non-trucking liability.
What do intermodal equipment providers require?
If you pull containers or chassis from ports and rail ramps, the Uniform Intermodal Interchange and Facilities Access Agreement (UIIA) sets the floor. Its insurance requirements include:
- Auto liability of $1 million combined single limit, on a policy marked Any Auto, Scheduled and Hired, or All Owned and Hired; All Owned or Scheduled Only is not acceptable
- The hold harmless endorsement (UIIE-1, CA 23 17, or TE 23 17B) on the auto policy
- Additional insured status on auto liability for every equipment provider you work with
- General liability of $1 million per occurrence
- Trailer interchange covering comprehensive and collision as well as fire and theft, which most equipment providers require, at limits that vary by provider
The majority of equipment providers also want some cargo coverage, and some require workers' compensation or employer's liability. The hired-auto wording matters because interchanged equipment isn't yours and won't appear on your schedule.
How to check your semi trailer insurance before the next load
Each step matches one kind of trailer to the coverage that should answer for it.
Step 1: List every trailer by owner
Owned, interchanged in, interchanged out, rented, power-only, and intermodal. Most fleets pull more than one kind in a month.
Step 2: Collect the paper behind each one
Interchange agreements, rental contracts, the UIIA, broker and shipper terms, and your lease. Each one says who pays for damage.
Step 3: Match each kind to a symbol
Read the symbols next to liability, physical damage, and trailer interchange on your declarations page. A missing 68, 69, or 70 is a missing coverage.
Step 4: Size trailer interchange to your costliest trailer
The limit applies to each trailer, so set it by the most valuable trailer you might pull, not the average one, and compare it with what your equipment providers require.
Step 5: Ask what loss of use costs you
Trailer interchange won't pay it, so find out what each agreement charges while a damaged trailer is out of service.
Step 6: Call your agent before you change the work
Adding power-only loads, intermodal work, or a new interchange partner changes which trailers you pull. Report it before the first load, not after a claim.
How Simplex helps with semi trailer insurance
We start with every trailer you pull and the paper behind it, then match the coverage to each one.
Tractor and trailer coverage
As a broker, we quote and place semi truck insurance, including UIIA and trailer interchange coverage, and a licensed agent follows up.
Physical damage for your trailers
Our physical damage insurance covers the trucks, tractors, and trailers you own after a collision, theft, fire, or other covered loss.
Leased owner-operators
Leased to a carrier? We quote non-trucking liability for owner-operators, and an agent can check it against your lease.
Frequently asked questions
Does semi truck insurance cover the trailer?+
What is trailer interchange insurance?+
Does semi truck cargo insurance cover the trailer?+
Is my trailer covered when another carrier pulls it?+
How much liability insurance does a semi truck and trailer need?+
Where this information comes from
The requirements below come from federal regulation, IRMI's insurance definitions, and the published terms of the UIIA and Amazon Relay, checked on October 19, 2026. Policy details quote ISO's Motor Carrier Coverage Form, CA 00 20 (2013 edition); insurers can change that wording, so confirm your own policy with your agent.
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1
eCFR — 49 CFR 387.9
Federal minimum liability: $750,000 for for-hire general freight, $1 million or $5 million for hazardous materials.
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2
eCFR — 49 CFR 376.31
The written agreement required when for-hire carriers interchange equipment.
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3
eCFR — 49 CFR 376.12
Lease terms on the carrier's control of leased equipment and who provides other insurance.
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4
IRMI — Trailer Interchange Insurance
Coverage for a carrier's legal liability for damage to other people's trailers.
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5
IRMI — Motor Carrier Policy
ISO's motor carrier form combining auto liability, trailer interchange, and physical damage.
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6
IRMI — Loss Payee
Who a loss payee is, such as the lender on financed equipment.
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7
IANA — UIIA Insurance Requirements
Auto liability, endorsement, additional insured, and trailer interchange rules for intermodal equipment.
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8
Amazon Relay — FAQ
Amazon's insurance list, including $50,000 of trailer replacement coverage.
Written by
Rigo Diaz
Founder & CEO, Simplex Group
Founder and CEO of Simplex Group, with more than 25 years leading the company and helping trucking entrepreneurs navigate compliance, insurance, and the day-to-day demands of running a carrier. Before founding Simplex, he spent more than six years in risk management, experience that continues to shape how he approaches insurance, compliance, and carrier risk today.
Published · Updated
Related articles and services
Know which policy answers for every trailer you pull
The tractor's policy usually answers for liability. Damage to the trailer depends on who owns it and on the paper you signed, and that is where the gaps are.
If you want a second look at your trailer coverage before you add power-only, intermodal, or a new interchange partner, talk to our team.