Ask an examiner what they want to see first, and the answer is usually records. The maintenance system a fleet runs today is invisible without the paperwork that proves yesterday’s - which is why the Guide to Maintaining Roadworthiness puts hard retention periods on the documents the system produces. The headline number is 15 months, and it applies more widely than many operators realise.
Two numbered requirements in the Guide set the floor. Drivers’ defect reports used to record faults and rectification work must be kept for at least 15 months. And records of safety inspections must be kept for at least 15 months for all vehicles - a requirement that expressly includes vehicles that have been removed from the operator licence or sold or otherwise disposed of. That last clause catches operators out: selling a truck does not end the record duty. The history travels with the operator, not the vehicle, and an examiner investigating last year’s fleet will ask for records of vehicles that have long since left the yard.
The defect-reporting detail goes further. Any report listing defects is part of the vehicle’s maintenance record and must be kept for at least 15 months, together with details of any assessment, the rectification work and the repairer. Electronic records of reported defects are acceptable and must be available for the same 15 months, along with the record of repair. So the rule is not just “keep the form” - it is keep the whole chain: what was found, what was decided, what was done, and who did it.
Two related retention expectations complete the picture. The Guide recommends completing and retaining “nil” defect reports - the driver’s confirmation that the daily check found nothing - because they are a useful means of checking that drivers are carrying out their duties and can be used for audit purposes. Nil reports carry a lighter touch: it is recommended they are retained for at least 3 months. And where safety inspections are contracted out, the formal written contract with the inspection agency or garage must be drawn up and retained on file - with the operator expected to view inspection records and regularly monitor the quality of the contractor’s work.
The retention window is calibrated to enforcement reality. Examiners investigating a prohibition, a test failure or an accident reconstruct a vehicle’s maintenance over a period that comfortably spans more than a single inspection cycle - and the annual test itself recurs yearly, so 15 months always captures at least one full test cycle plus the inspections around it. A fleet that can produce a continuous 15-month chain of daily checks, inspection reports and rectification records can demonstrate the system working over time; a fleet with gaps is asking the examiner to take the system on trust, which is not how examiners work.
Fifteen months of records across a fleet sounds like an archive problem, and handled badly it is. Handled well it is a process: defect reports flow in daily, are reviewed, actioned and filed by vehicle; inspection reports land on the same vehicle file with their brake tests and rectification notes; nil reports are retained on the lighter schedule; and a rolling purge clears what has aged out. Electronic systems make the chain easier to keep intact - the Guide accepts electronic defect records on the same 15-month term - but the discipline is the same either way: every vehicle, every document, every month accounted for, including the vehicles you no longer own. Records are the maintenance system’s memory. Fifteen months of memory is the price of proving you had one.
It helps to read the retention rules the way an examiner does. A DVSA investigation into a prohibition issued today asks: was this defect present, findable and unaddressed before the roadside stop? The answer lives in the defect reports and inspection records of the past year and more - which is exactly the period the 15-month rule captures. A fleet that produces a complete, continuous chain demonstrates that the prohibition was an anomaly in a working system; a fleet with holes in the record invites the conclusion that the system itself is the problem. That asymmetry is why retention deserves the same attention as inspection quality. The inspection finds the defect; the record proves the finding mattered. Operators who grasp that stop treating filing as admin and start treating it as evidence - because on the day it counts, evidence is the only thing that talks.