When Insurers Try to Intervene: What the Case Law Actually Says

Intervention is one of the most common tactics insurers use to challenge credit hire claims. The argument: the insurer offered the claimant a replacement vehicle directly, the claimant declined, and therefore the credit hire charges should be reduced or disallowed.

It sounds reasonable on the surface. But the case law places a far heavier burden on the insurer than most realise.

1. The Burden of Proof Is on the Insurer

The starting point is Copley v Lawn [2009] EWCA Civ 580. The Court of Appeal was clear: the burden of proving failure to mitigate rests on the defendant. The insurer must prove three things — that the offer was genuine, available, and comparable.

A letter saying "we offered a vehicle" is not enough. The insurer must produce evidence of the specific offer, including the vehicle, terms, delivery date, and conditions attached.

2. The Offer Must Contain Sufficient Detail

Manton Hire v Ash Manor Cheese [2013] EWCA Civ 1384 raised the bar. An intervention offer must contain sufficient information to allow the claimant to make an informed comparison:

• The specific vehicle model (not just "Group B" or "similar class").
• The location and delivery arrangements.
• The exact date it would be available.
• The duration and any conditions attached.
• Insurance arrangements, including any excess.

If any of these elements are missing, the claimant cannot make a meaningful comparison.

3. The Offer Must Be "Clear and Genuine"

Sayce v TNT (UK) Ltd [2011] EWCA Civ 1583 confirmed the defendant must prove the offer was clear and genuine. This is where the "basket of services" argument becomes critical: credit hire agreements typically provide CDW, delivery and collection, like-for-like replacement, and nil excess. If the insurer's offer does not match this, it is not a genuine alternative.

The nil-excess point is particularly important. Bee v Jenson [2007] EWCA Civ 923 confirmed that a claimant can reject an offer that would expose them to a contractual liability they would not otherwise face.

4. The "True Cost" Requirement

Copley v Lawn also established that the claimant must be informed of the "true cost" of the hire to the defendant — meaning the insurer should disclose the daily rate they would have paid their supplier.

In correspondence, this creates a practical opportunity. Requesting the actual letter, full T&Cs, and the insurer's true cost puts them on the back foot.

5. What a Strong Intervention Response Looks Like

• Challenge the burden under Copley v Lawn.
• Demand specifics under Manton Hire.
• Test the offer against the basket of services under Sayce v TNT.
• Raise the nil-excess point under Bee v Jenson.
• Request the true cost under Copley v Lawn.

This puts the insurer in a position where they must justify their argument with evidence, not assertions. In our experience, the majority of intervention challenges cannot survive this level of scrutiny.

Key Authorities

• Copley v Lawn [2009] EWCA Civ 580
• Manton Hire v Ash Manor Cheese [2013] EWCA Civ 1384
• Sayce v TNT (UK) Ltd [2011] EWCA Civ 1583
• Bee v Jenson [2007] EWCA Civ 923

Disclaimer: this article is general guidance, not legal advice.