Is PMI every 6 weeks a legal requirement?

No. Six weeks is a common interval for tippers because their work is arduous, but the legally binding figure is the inspection frequency you committed to on your operator licence. If that says 6 weeks, you must inspect every 6 weeks; if it says 8, then 8. You can apply to change it, but you must keep to whatever is current.

A PMI (preventative maintenance inspection), also called a safety inspection, is a scheduled examination of a vehicle or trailer against a set list of items — brakes, steering, tyres, lights, body and more — to confirm it is roadworthy. It is separate from the driver's daily walkaround check and from the annual MOT.

Compliance guide

How often should a tipper be safety inspected?

Q: How often should a tipper be safety inspected?

There is no single legal number — the required interval is the one stated on your operator licence. In practice, tippers doing arduous on/off-road work are commonly inspected every 6 weeks, while less arduous vehicles may run at 8, 10 or 13 weeks. DVSA expects intervals to be time-based and appropriate to the vehicle's age, mileage and type of work.

Q: How long must PMI records be kept?

Safety inspection (PMI) records must be kept for at least 15 months and be readily available for DVSA inspection, alongside walkaround and defect records, so a complete maintenance history is available.

Updated September 2026 · ~4 min read

Short answer: There's no single legal number. The interval you must keep to is the one stated on your operator licence. In practice, tippers doing arduous work are usually inspected every 6 weeks; lighter-use vehicles may run at 8, 10 or 13 weeks. DVSA wants intervals to be time-based and matched to the vehicle's age, mileage and type of work.

The interval is set by you — on your O-licence

When you apply for an operator licence you commit to a maximum inspection frequency. That figure becomes your legal obligation: whatever it says, you have to keep to it. DVSA's Guide to Maintaining Roadworthiness asks operators to set a time-based interval (weeks, not mileage) that suits the vehicle — and to review it as vehicles age or work harder.

Typical tipper frequencies

6 weeks — common for tippers and grab lorries because on/off-road, heavy, dusty work is arduous.
8–10 weeks — mixed or lighter road work.
13 weeks — the longer end, usually only for low-mileage, low-stress vehicles.

Newer isn't always longer: a brand-new tipper thrashing a quarry may still warrant 6-weekly. The test is the work, not just the age.

What a PMI actually is

A PMI (preventative maintenance inspection), or safety inspection, is a scheduled check against a defined list — brakes, steering, tyres, suspension, lights, body, tipping gear — to confirm the vehicle is roadworthy. It is separate from the driver's daily walkaround and from the annual MOT. A laden roller brake test (or an approved alternative) should form part of most inspections.

What DVSA checks

That you actually inspect at your stated interval — gaps and overdue PMIs are a red flag.
That inspections are signed off and any defects are rectified and recorded.
That records are kept for at least 15 months and are easy to produce. See our guide on how long to keep walkaround and maintenance records.
That there's a working link between the driver walkaround, defects and the PMI system.

An overdue PMI is one of the fastest ways to lose your operator's good repute. A tidy, on-time inspection history is one of the best defences at a DVSA visit.

Never miss a PMI again

Raahi tracks every truck and trailer's PMI, MOT, tax and calibration dates and reminds you before they're due — with the full inspection and defect history in one place.