A mate of mine runs an eight-vehicle fleet out of a depot near Birmingham. Flat-deck and curtainsider work, mostly construction aggregate and retail distribution. He's been doing it for eleven years, knows his drivers, keeps a clean ship. Last year, two of his vehicles were issued immediate PG9 prohibitions at DVSA roadside checks within six weeks of each other. Both for brake-related defects. Both defects that should have been caught on the previous PMI.
Two months later, he had a call-up letter from the Traffic Commissioner's office. Not a public inquiry — a maintenance investigation. But the TC's letter made clear that if the investigation findings were not satisfactory, a referral to public inquiry was the next step, and at a public inquiry, his operating licence would be at risk.
He spent three weeks pulling together documentation, records, and evidence before the meeting. He kept his licence. He also made significant changes to how his maintenance system worked. Here's what the TC was looking at — and what made the difference between keeping the licence and losing it.
What the operator's licence actually commits you to
When you're granted a goods vehicle operator's licence, you sign undertakings. These are not guidelines or best-practice suggestions. They're conditions of the licence, and breaching them is grounds for the TC to revoke it, suspend it, or attach restrictions.
The maintenance-related undertakings, summarised from the standard GV79 application form, commit the operator to:
- Ensuring vehicles are kept in a fit and serviceable condition at all times
- Ensuring regular safety inspections are carried out at appropriate intervals
- Keeping records of all safety inspections, maintenance work and driver defect reports for at least 15 months
- Ensuring drivers carry out and report walkaround checks
- Ensuring the nominated transport manager (or operators themselves if they hold the CPC) actively manages compliance
- Ensuring driving licence and driver CPC checks are carried out on all drivers
The fifteen-month record retention figure comes up repeatedly in TC hearings. It covers two annual test cycles with a reasonable margin and is the standard window a TC examines when reviewing maintenance compliance. If records for the previous 15 months can't be produced, the TC draws the inference that the system wasn't functioning.
What triggers a call-up
The Traffic Commissioner doesn't have the resources to investigate every operator proactively. They work from referrals and triggers. The most common routes to a call-up letter are:
OCRS score movement. The Operator Compliance Risk Score is updated each time a vehicle from your licence has a DVSA encounter — roadside check, targeted stop, test site visit. A vehicle issued with a PG9 (immediate prohibition) generates a significant negative scoring event. Two PG9 prohibitions in six weeks will move most small fleets from green into amber or red. An amber OCRS alone may trigger closer scrutiny; red almost always does.
Serious or immediate prohibition pattern. Individual prohibitions are recorded against the operator licence. A pattern — even if each individual event looks minor in isolation — attracts attention. The TC is looking at whether the operator has systemic maintenance failures, not just bad luck.
Traffic examiner referral. DVSA traffic examiners can investigate operators directly. If a TE visit to your premises raises concerns about your maintenance records, your systems, or your transport manager's engagement, they can refer the case to the TC directly.
Complaint. Complaints about vehicles can be made by the public, by other operators, by local authorities. The TC's office investigates credible complaints.
The maintenance investigation vs the public inquiry
A maintenance investigation is less formal than a public inquiry and is conducted by DVSA on behalf of the TC. Its purpose is to examine whether the maintenance undertakings are being met. The outcome can be: satisfactory (no further action), advice or warning letter, undertakings about future practice, or referral to a public inquiry.
A public inquiry is heard by the Traffic Commissioner or a deputy TC directly. The outcomes available are much broader: formal warnings, imposition of conditions, suspension of licence, curtailment (reducing the number of vehicles authorised), and revocation. Revocation ends the business's ability to operate under that licence — and the TC can also take action against the transport manager's CPC, which prevents them from being named as TM on any operator licence in future.
The step from maintenance investigation to public inquiry is not automatic. What happens in the maintenance investigation — the quality of the records produced, the credibility of the explanation for what went wrong, and the evidence that the problem has been addressed — largely determines whether the referral is made.
What the TC looks at in a maintenance investigation
In my mate's case, the investigator wanted to see three things above everything else: the PMI records for the two vehicles that received PG9s, the driver defect report records for those vehicles over the six-month period before the prohibitions, and evidence that the defects found by DVSA had been identified internally before the roadside stops — or, if not, an explanation of why the internal system missed them.
The answer in his case was uncomfortable. The PMI records existed but showed the brake defect had been noted as a minor advisory two cycles before the prohibition, and no follow-up inspection had been recorded. The defect report records were incomplete for one of the vehicles — the driver had been verbally reporting minor issues but not always completing the written report, and nobody had been chasing the written record.
What saved him was the combination of: records that existed and could be produced (even if they showed a process gap), a transport manager who could demonstrate they'd been actively engaged and had implemented corrective action, and a prior clean history that gave the TC some context for treating this as a process failure rather than a systemic disregard for safety.
The transport manager's role in all of this
Transport managers carry personal responsibility for the management of driver compliance and vehicle maintenance under their operator licence. The TM's CPC qualification is a condition of the licence's continued validity — if the TM is found to lack good repute (through deliberate breach of regulations, persistent neglect of obligations, or making false statements to regulatory bodies), the TC can disqualify them from the role.
In a small fleet, this is often the owner-driver who holds both the licence and the TM role. The TC's test in a maintenance investigation is whether the TM was genuinely engaged in managing compliance — not just nominally responsible, but actually looking at records, following up on defects, and making decisions. A TM who can't explain the maintenance system in detail, or who clearly hasn't been reading the PMI reports, is in a worse position than one who can walk the investigator through every decision made.
For the purposes of the investigation, the TM is the face of the operation. Prepare accordingly.
After the investigation
If the maintenance investigation results in a formal warning or written undertakings, those are recorded on the operator's file and taken into account in any future proceedings. A second maintenance failure within a few years of a first one is treated much more seriously than the first event.
The practical upshot: fix the system, not just the paperwork. TC investigators are experienced at distinguishing operators who have genuinely improved their process from operators who have created a stack of retrospective paperwork to explain away a pattern. Genuine improvements — tighter PMI schedules, reliable defect reporting, a TM who's demonstrably engaged — are what keep licences intact long-term.
My mate now has a standing PMI calendar, a defect report checklist that every driver signs off electronically after every shift, and a TM review meeting once a month where the records get looked at properly. It took a call-up letter to get there. It didn't have to.
If you're tracking driver hours, rest periods, and compliance alongside your maintenance records, ShiftOwt covers the 561 and WTD side — £5.99/month for drivers, fleet and agency pricing on request.