Safety inspection intervals for lorries and trailers. How to pick the gap, and how to keep to it.

By Scott Woodfield, who builds HGVault. Last checked 7 November 2026.

Ask a fleet engineer why the artics are on six weeks and the answer is often that they’ve always been on six weeks. That’s fine for as long as the work still fits the gap. A goods operator’s safety inspection interval, the PMI in most workshops, is a commitment given to the traffic commissioner and recorded on VOL. DVSA examiners then judge it against what your own inspection sheets keep finding.

In brief

• Your licence carries an undertaking to inspect at stated intervals and keep the records, and an unfulfilled undertaking is a ground for action against the licence.
• DVSA’s table gives 4 to 13 weeks depending on the work, with 6 weeks as the minimum for lorries and trailers aged 12 years or more.
• Trailers that aren’t permanently coupled are judged on their own work and mileage, and VOL takes a mixed frequency for them.
• Inspections are planned in ISO weeks at least 6 months ahead, and an interval shouldn’t be stretched until VOL has been updated.

Where the interval comes from

Section 13C(4) of the Goods Vehicles (Licensing of Operators) Act 1995 requires satisfactory facilities and arrangements for keeping the vehicles used under a licence in a fit and serviceable condition. When you apply, the traffic commissioner looks for assurances that you’ll carry out regular safety inspections at specified intervals and keep records of them and their results. Those are the undertakings on your licence, once known as statements of intent. One that hasn’t been fulfilled is among the grounds on which a licence can be revoked, suspended or cut back.

The working reference is DVSA’s Guide to maintaining roadworthiness, last updated on 28 April 2025 and approved by the Upper Tribunal. Traffic commissioners start from it when they decide whether your arrangements are satisfactory. It uses must for the law and for licence undertakings, and should for best practice you’re expected to follow unless you can show your own way gets the same result.

Reading DVSA’s frequency table

The guide says operational needs must not override safety, and asks for a time-based programme where practical. The interval should match how fast the vehicle is likely to wear, judged on its age and type, the manufacturer’s recommendations, what it carries and the equipment fitted to it, the work it does, the terrain, and the distances, speeds and hours it covers. It gives this table of examples.

For quarry work, building and land reclamation sites, and vehicles carrying corrosive substances, the guide advises inspecting more often than the table suggests. A tipper running muck away from a groundworks job belongs at the short end of the table, or past it.

The last row catches out a lot of hauliers with older trailers. It covers vehicles and trailers alike, because national figures show MOT failure rates climbing with age, and older kit picks up more defects in service. Low mileage and light work can justify a longer gap, if you can show why.

Intermediate checks

An interval doesn’t have to treat every component the same. The guide allows intermediate safety checks on high-wear items between full inspections, documented and clearly labelled as intermediate checks. Its case study of All Construction, a made-up operator with six 7.5 tonne trucks working on the road and on building sites, shows how. Most of the defects at their 4-weekly inspections were suspension, so they checked the suspension every 3 weeks and inspected the whole vehicle every 6. After six months the suspension parts were being replaced before they failed, nothing else had got worse, and VOL was updated to 6 weeks.

New operator or experienced one

A new operator has no history to read, so the guide’s advice is to be cautious and inspect more often rather than less. Its case study here is N E Hall, a new haulier expecting 100,000 miles a year on arduous work, which picked 4 weeks from the table.

The guide doesn’t define an experienced operator, but suggests what might count, such as more than 3 years trading under this licence or a previous one, or more than a year with a DVSA visit marked satisfactory. Experience buys freedom to tailor the schedule, including running more than one system across a fleet. It doesn’t buy freedom from watching the results. After any change the guide suggests checking roadworthiness monthly and going back to the old schedule if defects rise.

Its removals company case study, Move4U, shows what going back looks like. They stretched their vans and trucks from 4 weeks to 12, saw a large rise in defects and more roadside prohibitions within six months, and settled on 6 weeks, where a year’s monitoring brought defects back to the level they’d had at 4.

Mileage-based intervals

A mileage-based programme is allowed as long as it’s linked to time. The guide’s courier, CJS Couriers, found 4 weeks too often for its local work but saw defects spike whenever national and continental runs picked up, so it moved to every 2,000 miles or 6 weeks, whichever comes first. VOL only takes a time-based frequency, so a mileage-based system goes on as its expected maximum in time, up to 13 weeks, with the mixed frequency box ticked. For vehicles used for part of the year the guide works in equivalent annual mileage, so 20,000 miles over six months counts as 40,000 a year.

Trailers get their own interval

The guide treats a trailer as a vehicle, and a trailer gets an interval of its own. Trailers that aren’t permanently coupled but are in regular use are assessed on their own work and expected mileage. The unit that happens to be pulling one this week doesn’t come into it. VOL records trailer frequencies separately from vehicle frequencies, and the mixed frequency box covers trailers on different gaps.

The guide’s example is an operator with tipping trailers on 6 weeks because of the hard work, also pulling customers’ light-load trailers on traction-only work that are inspected every 12. Where third-party trailers aren’t on your own frequency, the default is no more than 13 weeks. Hold on to a non-UK trailer for more than 13 weeks and it should be inspected in line with your stated trailer frequency.

Trailer intervals drive the brake testing too. Where EBPMS isn’t used, the guide expects at least four laden brake tests a year, evenly spaced. A trailer on 12 weeks without EBPMS therefore needs a laden test at every inspection, while a lorry on 6 weeks gets there with one at every other inspection. Our guide to trailer safety inspections goes through the brake rules in full.

Planning in ISO weeks

The guide recommends planning in ISO weeks, which run Monday to Sunday, with each inspection done within the ISO week it falls due. Its rule on early inspections is the one people trip over. Take a trailer on 8 weeks, inspected in week 3, so due in weeks 11, 19 and 27. If it comes in early in week 17, it can’t then run on to week 27. Either it’s inspected again in week 19 and stays on the original plan, or the 8 weeks restart from week 17, giving weeks 25, 33 and so on.

Plan at least six months ahead, on a wall planner or a digital system that schedules the next inspection from the last. The plan should hold every lorry, van and trailer with its annual test date, and the other dates that come round, such as tachograph calibration and lifting equipment. On a goods fleet that means tail lifts. HSE’s LOLER intervals are every 6 months for equipment used to lift people and every 12 months for other lifting equipment, unless a competent person’s examination scheme sets others, so a tail lift the driver rides up on is in the 6 month group. Planning the year around the annual test saves doing the cleaning and preparation twice.

Question 4d of DVSA’s maintenance investigation asks whether an effective forward planning system is in use. A planner used inconsistently is marked mostly satisfactory. No planner, or one that doesn’t work, is unsatisfactory.

What counts as late

Question 4c is where intervals get marked. An occasional slip into the next ISO week, or an isolated missing first use inspection, is mostly satisfactory. A system that’s obviously not managed, with the undertaking clearly not being met, is unsatisfactory. So is a run of defects on the sheets that shows the interval is too long, which means a lorry inspected bang on time every time can still fail question 4c.

A lorry or trailer declared off the road is recorded on its maintenance file with the date and the reason. If the VOR runs over its next planned inspection the schedule can be suspended, which suits seasonal trailers and long repairs. It can’t go back into service until an inspection confirms it’s roadworthy, and the plan can then restart from that date. Examiners compare VOR records with tachograph data, telematics or schedules, so a unit marked off the road that turns up on a trunk run will be found.

A vehicle in service has no such slack past its due week, because the guide only lets the schedule be suspended for one that’s VOR. If an inspection is missed, the safe course is to take the vehicle off the road until it’s been inspected, and to record that inspection in full with its brake assessment. Then decide whether to rejoin the old plan or restart from the new date, and write down why it happened and what you’ve changed.

Letting the sheets set the gap

The guide’s test of an interval is what the inspections find. Lots of faults on a regular basis can mean too few inspections, walkarounds done badly or defects not being put right. Few or none can mean the interval is shorter than it needs to be, or that the inspections aren’t thorough enough. It also suggests a technically competent third party re-inspects from time to time, whether the work is done in-house or contracted out.

Contracting out doesn’t move the interval off your desk. The written contract has to set out the vehicles covered, the inspection frequency and the type of check, and the maintenance provider shown on VOL has to be kept up to date. GOV.UK’s page on maintaining your vehicles puts it simply. You’re still responsible for the condition of your vehicles and trailers, even if someone else maintains them. This is general information, and the guide itself is the place to check anything your licence depends on.

In HGVault each lorry, van and trailer has its own inspection interval and the ISO week of its next inspection, and the plan runs on through this year and next, with annual tests, tachograph calibration and tail lift LOLER dates on the same calendar. Before a technician can sign an inspection sheet it checks for late signing with no VOR cover. See the fleet office and goods licence and safety inspections, or look round the planner in the walkthrough.

Sources

• GOV.UK (DVSA), Guide to maintaining roadworthiness
• GOV.UK (DVSA), Guide to maintaining roadworthiness, publication page and change history
• legislation.gov.uk, Goods Vehicles (Licensing of Operators) Act 1995, section 13C
• GOV.UK, Being a goods vehicle operator, maintaining your vehicles
• GOV.UK (DVSA), Maintenance investigations, questions
• HSE, Thorough examinations and inspections of lifting equipment