Your O-licence comes with an undertaking to keep vehicles roadworthy, and the planned safety inspection schedule, often called a PMI programme, is how you prove it. Get the intervals wrong and everything downstream starts to wobble: walkaround checks stop catching faults early, MOT pass rates slide, and roadside prohibitions follow. DVSA’s guide to maintaining roadworthiness is the document Traffic Commissioners use as the starting point for whether your arrangements are satisfactory, so it is the right place to set your intervals from.
There is no single statutory interval. The guide expects inspections to follow a time-based pattern where practical, with the frequency set by assessing how fast each vehicle is likely to deteriorate in service. The factors it lists are:
In practice, inspection frequency would normally range between 4 and 13 weeks. A trunking artic on motorway work sits at the long end; a tipper on quarry work sits at the short end. The guide’s own example is a mixed fleet: tipping trailers on demanding work inspected every 6 weeks, while third-party trailers on light traction-only work are inspected every 12, with the vehicle operator licensing service recording a mixed trailer frequency. Mileage-based programmes are acceptable for some operations but must still be linked to time, so a vehicle cannot sit unused past its date.
Age matters explicitly. Because MOT failure rates rise with vehicle age, the guide indicates a minimum safety inspection frequency of 6 weeks for vehicles and trailers aged 12 years or older, extendable only where usage is genuinely light, such as low mileage in easy conditions. If you run older kit, that 6-week default is the number an examiner will have in mind.
New operators get specific attention too. With no maintenance history to draw on, you set the interval from the work, conditions, vehicle age and mileage, then monitor hard in the early months to confirm the interval is actually keeping the vehicles safe, and tighten it if defects say otherwise.
The scope of a safety inspection should at least cover everything examined at the annual test, including a laden roller brake test where appropriate for the vehicle type. Modern fleets increasingly use an electronic braking performance monitoring system (EBPMS) as part of that picture, and the guide has been updated with more detail on using EBPMS reports and on braking performance assessment. The point the guide makes forcefully is that the O-licence standard is “fit and serviceable”, which can be higher than a bare MOT pass: brakes must be maintained in good and efficient working order and properly adjusted, and that duty reaches into driver assistance systems as well.
The inspection only counts if you can show it happened. The guide requires:
That trailing obligation surprises people: sell a truck in month two and you still keep its records for the full period, because the traffic commissioner can ask about the whole window.
Safety inspections sit on top of the daily walkaround check, not instead of it. The driver remains legally responsible for the vehicle’s condition in use, and at least one walkaround check must happen every day, or at least once in every 24-hour period the vehicle is used. Operators can delegate the check to a responsible person, but the driver then needs evidence it was done and the vehicle is free of safety defects. Vehicles on arduous or off-road work may need several checks in a day. Drivers are also expected to monitor the vehicle on the road and react to warning lights, vibrations and other symptoms between checks.
Two reach-beyond-the-obvious points. Light goods vehicles that are in scope of operator licensing must be maintained in line with the guide, full stop. And for vehicles outside licensing, such as vans under the threshold, the guide says operators are still expected to run an appropriate maintenance regime, because the traffic commissioner can take the condition of out-of-scope vehicles into account. A badly maintained van fleet is not a safe corner to hide in.
Start from the guide’s factor list and score each vehicle or vehicle group honestly: age, work type, terrain, annual mileage. Set the interval, write it down with the reasoning, and put it in the maintenance planner with the MOT dates. Then watch the evidence: first-time MOT pass rates, defect rates between inspections, brake test results, roadside encounters. Defects trending up means the interval is too long, whatever the spreadsheet says. The guide is explicit that operational needs must not override safety considerations, which in practice means the Christmas peak is not a reason to stretch an interval.
The operations that sail through maintenance investigations treat the interval as a living decision backed by records. The ones that struggle are running an interval someone chose years ago, for a fleet and a workload that no longer exist.