Subcontracting is how the haulage industry breathes - overflow work, specialist kit, geographic gaps. It is also how compliance failures arrive wearing your customer’s consignment note. When a subcontractor’s truck moves your customer’s goods, the road traffic law is theirs but the commercial and reputational consequences are yours, and ‘we didn’t know’ is a verdict, not a defence. Due diligence is the discipline that separates deliberate subcontracting from hopeful subcontracting.
The single most important check is also the easiest, because the government publishes it. The official Find vehicle operators service lets you search for goods and passenger vehicle operators by name, address or licence number, and see the public register record: whether the operator holds a licence, what it authorises, and the regulatory history attached to it. This is the first gate and it is binary: no valid operator licence, no subcontract - a business moving goods for hire without one is illegal, and a contractor who knowingly uses them inherits the taint.
But the register gives more than existence. The licence record shows the operator’s standing - curtailments, suspensions, public inquiry outcomes - the traffic commissioner’s fingerprints on the business. An operator whose licence was cut from fifty vehicles to twenty last year is telling you something about their compliance trajectory, and the check that takes two minutes tells you to ask why before the load moves.
The licence proves legality to operate; it does not prove the load is protected. The document set that should sit on file before the first job runs to a short list: goods in transit insurance at a level matched to the loads you actually hand over (and a certificate current today, not at last year’s onboarding); public liability cover; and evidence of the operator’s own maintenance and drivers’ hours systems proportional to their size. Larger or regular subcontractors justify deeper looks - their OCRS position if they will share it, their earned recognition status if they have it, references from other contractors.
The insurance point deserves weight: if the subcontractor’s GIT cover is £10,000 a load and your customer ships £80,000 pallets, the gap is your problem. Checking the certificate against the actual work is the diligence; filing a certificate that was never read is theatre.
The vetting conversation is also the moment to set the contractual frame, because after the incident is too late. Written terms should cover: whose conditions the work moves under; insurance obligations and evidence; compliance warranties (licence maintained, drivers’ hours observed, vehicles roadworthy); the right to audit or to see records when an incident needs investigating; and what happens on loss, damage or delay. None of this needs a law firm for routine work - it needs a standard subcontract pack that every subbie signs before the first load and refreshes annually with new certificates.
The failure pattern in subcontractor management is diligence that stops at the door: checked once, filed, forgotten. Licences get curtailed mid-relationship; insurance lapses; the good operator you onboarded gets busy and starts subbing your work onward to someone you have never heard of. The controls are periodic: re-run the register check on a cycle (the Find vehicle operators search is free and instant), refresh certificates annually, and make onward subcontracting without consent a contractual breach - because the chain you cannot see is the chain that hurts you.
And keep the records of the checking itself. When something goes wrong - an accident, a lost load, an insurance claim - the file that shows you checked the licence, verified the insurance and set written terms is the difference between a business that managed its supply chain and one that hoped.
Subcontractor due diligence is a short list done repeatedly: verify the operator licence on the public register, hold current insurance matched to the loads, sign written terms, re-check on a cycle. The register search costs two minutes; skipping it can cost the customer.
Much subcontracting in haulage is with owner-drivers and micro-fleets, and due diligence has to scale without becoming theatrical. The core checks do not shrink with the subcontractor: the licence check on the public register works the same for one truck as for a hundred, and the insurance certificate matters as much. What scales down is the depth - a one-truck owner-driver will not have an OCRS history to review or written maintenance systems to inspect, but they will have a licence, a test history and insurance, and checking those three takes minutes. The red flags shrink too: no licence, insurance that ‘is being sorted’, reluctance to put terms in writing - each is a walk-away at any fleet size.