Trailer inspection checklist: pre-trip items, the DOT form and the annual inspection

Updated November 2, 2026 · Reviewed by Israel Margulies, founder and CEO of High Point GPS

A trailer inspection checklist covers the coupling, brakes and air or electric connections, lights and reflectors, tires, wheels and rims, suspension and frame, and the load securement, checked before every trip. Federal rules for commercial motor vehicles add two more layers: a written driver vehicle inspection report when a driver finds a defect, and an annual periodic inspection of every trailer, with proof carried on the trailer. The checklist and form below follow 49 CFR parts 392, 393 and 396.

What DOT expects a trailer check to cover

Under 49 CFR 392.7, a commercial motor vehicle may not be driven unless the driver is satisfied that its parts and accessories are in good working order. For a trailer, the items on that list that apply are service brakes including trailer brake connections, lighting devices and reflectors, tires, coupling devices, and wheels and rims. Section 392.9 adds the cargo: the driver checks the load and its securement before leaving, again within the first 50 miles, and then at each change of duty status, every 3 hours or every 150 miles, whichever comes first.

Those rules set the minimum. A useful checklist names the parts on your own trailers, so a driver pulling a lowboy checks the neck locks and a driver pulling a reefer checks the unit.

Pre-trip trailer inspection checklist

Walk the trailer in the same order every time: coupling, front, one side, rear, other side. Mark each line OK or defect, and write what you found next to any defect.

Coupling: fifth wheel jaws locked around the kingpin, no gap between the plate and the trailer, release handle in the locked position
Coupling (pintle or ball): latch closed and pinned, safety chains or cables attached to the tow vehicle’s frame with no extra slack
Air lines and gladhands: seals in place, no audible leaks, lines clear of the deck plate; electrical cord connected and not chafed
Landing gear fully raised and crank handle stowed
Brakes: no audible air leaks at chambers or hoses, nothing hanging or broken at the slack adjusters; on electric brakes, breakaway switch and battery in working order
Lights and reflectors: clean, working and not blocked by the load (49 CFR 393.9)
Tires: inflated, no flats or audible leaks, no exposed ply or belt, no tread or sidewall separation, tread at least 2/32 inch in a major groove
Wheels and rims: no cracks, no missing or loose lug nuts, no rust streaks around studs; hub caps in place, no oil or grease thrown from seals
Suspension and frame: springs and hangers intact, air bags inflated, no cracked crossmembers or rails
Doors, ramps, gates and tarps closed and secured
Cargo and tie-downs: load distributed and secured, binders tight, chains and straps undamaged
Annual inspection decal or report on the trailer

What a DOT trailer inspection form must record

The form most fleets call a trailer inspection sheet is the driver vehicle inspection report (DVIR) in 49 CFR 396.11. At the end of each day’s work, the driver prepares a written report on each vehicle operated, trailers included. The report must cover the service brakes including trailer brake connections, parking brake, steering, lighting devices and reflectors, tires, horn, wipers, mirrors, coupling devices, wheels and rims, and emergency equipment.

The report identifies the vehicle and lists any defect that would affect safe operation or lead to a breakdown, and the driver signs it. The rule doesn’t require a report when the driver finds no defect, but you can still keep a daily record for every trailer. The carrier must repair listed safety defects before the vehicle runs again, certify on the report that each one was fixed or didn’t need repair, and keep the report and certifications for three months. Reports can be electronic.

Trailer number or other identification
Date, driver name and signature
Each defect found, with its location on the trailer
Repair certification: fixed, or repair unnecessary, signed by the carrier or its agent
Next driver’s signature confirming review (49 CFR 396.13)

The next driver’s review and towed units

Before driving, 49 CFR 396.13 requires the driver to be satisfied the vehicle is safe, review the last report when one was required, and sign it to acknowledge the repair certification. That signature requirement doesn’t apply to defects listed on a towed unit that is no longer part of the combination.

If you run drop-and-hook, a trailer may meet a new tractor every day. Its defect report has to follow the trailer, not the tractor that pulled it last, or the next driver can’t review it. Keep the report attached to the trailer’s own record.

The annual DOT trailer inspection

Section 396.17 requires every commercial motor vehicle to pass a periodic inspection at least once every 12 months, and it counts each vehicle in a combination separately. For a tractor pulling a semitrailer and a full trailer, the tractor, the semitrailer, the full trailer and any converter dolly each need their own inspection. Proof must be on the vehicle: the inspection report itself, or a sticker or decal showing the date, where the report is kept, the vehicle’s identification and a certification that it passed.

The inspection must cover at least the items in Appendix A to part 396. On a trailer, that includes the brake system, coupling devices, lighting, suspension, frame, tires, and wheels and rims. A few of the trailer brake items that fail an annual inspection:

No braking action on an axle that must have brakes
Pushrod stroke past the readjustment limit, measured with reservoir pressure of 80 to 90 psi and the brakes fully applied
Air drum brake lining under 1/4 inch at the shoe center on a non-steering axle
Brake hose damaged through the outer reinforcement ply, bulging, or leaking audibly
Electric brakes: no braking on a wheel that must have brakes, or a missing or inoperable breakaway device

Safety chains and couplers on full trailers

Full trailers and converter dollies on a tow bar must have safety devices that keep the trailer attached if the tow bar fails, under 49 CFR 393.70(d). The device can’t attach to the pintle hook itself, may have no more slack than the trailer needs to turn, and must be rated for at least the gross weight being towed. With chains or cables, that means two of them, or a single bridle attached at two points as far apart as the frame or axle allows.

Check chain hooks and links for stretch, cracks and road wear at every pre-trip, and replace a chain that has been dragging.

Running trailer inspections in FleetZap

In FleetZap each trailer carries a QR label. The driver scans it with a phone and gets your trailer checklist without signing in, built from pass/fail, reading, photo and signature steps, with required steps that must be answered before the check closes. A failed item creates one repair work order for the shop, linked to the inspection, and dispatchers are alerted; a meter reading entered on the check is saved when it’s higher than the last one.

Annual inspections, registrations and plates go in as compliance items on each trailer, with reminders before they come due and an optional work order when the inspection is due; when it’s done, the item renews by its interval. Trailers without their own meter follow a calendar maintenance schedule, or miles from the towing truck or a GPS tracker where you have them. FleetZap records the checks and repairs; it doesn’t certify DOT compliance.

Key takeaways

If a trailer type has a part the federal list doesn't name (ramps, neck locks, a reefer unit), add it as its own checklist line before the first trip.
In drop-and-hook yards, check weekly that every open trailer defect is visible from the trailer's own record, not only from the last tractor's report.
Schedule each trailer's and dolly's annual inspection on its own date, so one late tractor doesn't push the whole combination past 12 months.
Record pushrod stroke and lining thickness as numbers on the annual and PM sheets; a trend over three inspections tells you when to reline before it fails.

Sources

FleetZap Maintenance

Work orders, PM, parts, compliance, assets and KPIs. Explore FleetZap Maintenance.

Frequently asked questions

What should be on a trailer inspection checklist?

Cover the coupling (fifth wheel or pintle, safety chains), air lines or brake wiring, landing gear, brakes, lights and reflectors, tires, wheels and rims, suspension, frame, doors and the load securement. Add parts specific to your trailers, such as ramps, necks or a reefer unit. Mark each item OK or defect and write a note for every defect, so the shop knows what to fix.

Is there a DOT trailer inspection form?

FMCSA doesn’t publish one mandatory form. The rule in 49 CFR 396.11 sets what the driver vehicle inspection report must contain: the vehicle’s identification, any defect affecting safety, and the driver’s signature, covering items like brakes, trailer brake connections, lights, tires, coupling devices and wheels. The carrier then certifies repairs. Paper or electronic forms both work if they record those items.

How often does a trailer need a DOT inspection?

A commercial trailer needs a periodic inspection at least once every 12 months under 49 CFR 396.17, and proof of it, such as the report or a decal, must be on the trailer. Drivers also check it before each trip and report defects at the end of the day. Every trailer and converter dolly in a combination needs its own annual inspection.

What is the minimum tread depth on trailer tires?

Under 49 CFR 393.75, trailer tires need a tread groove depth of at least 2/32 inch measured in a major tread groove, not at tie bars or humps. The stricter 4/32 inch rule applies to front tires on buses, trucks and truck tractors. Any tire with exposed ply or belt, a separation, a flat or an audible leak can’t be used.

How long do you keep trailer inspection reports?

Motor carriers must keep driver vehicle inspection reports, the repair certification and the driver’s review signature for three months from the date the report was prepared, under 49 CFR 396.11. Annual inspection reports are kept for 14 months from the inspection date under 49 CFR 396.21, where the trailer is housed or maintained. Keeping both in each trailer’s maintenance history makes them easy to produce at an audit.

Book a demo · Try the live demo