The High Court has ruled that a mistake on a Part 36 offer can be altered after a claimant sought to rectify what was an ‘obvious’ error. The offer, which also included an ampersand instead of a percentage symbol, seemed to suggest the defendant would only have to pay 20% of the damages claimed, when in fact the solicitors were seeking 80%.

Master Thornett said Part 36 was not a ‘hermetically sealed’ process and that the doctrine of common law mistake could apply to Part 36 where a clear and obvious mistake had been made.

Claimant solicitors in O’Grady v B15 Group Ltd had put forward a Part 36 on the issue of liability last February following a fatal road traffic accident.

The solicitors had already rejected the defendant’s offer on the basis of a 60/40 split in favour of the claimant, then wrote: 'The claimant offers to resolve the issue of liability of on 80/20 basis. For the avoidance of doubt if the defendant accepts this offer it will only be required to pay 20& of the claimant’s damages.’

The following day, the solicitors sent a further email to make clear the offer was intended to be 80/20 in the claimant’s favour. The claimant then issued an application for permission to withdraw the offer or change its terms.

In a one-day hearing last month, the claimant argued there was no reason, either by reference to Part 36 itself or to case law, why the Part 36 offer – where the mistake was known to the recipient – should not be effective and binding. They added it was ‘surely always obvious’ that the email with the typo was not written as intended. It was not submitted that any mistake would be acceptable, but in this case it must have been clear that the claimant was not offering a 20/80 split, having already turned down a 60/40 offer.

The defendant’s position was that Part 36 was a ‘self-contained code’ with no basis anywhere for allowing a mistake. It was further submitted that if the rules committee had wanted a provision that an offer could be withdrawn or varied it would have provided one.

The master said the defendant’s arguments were inconsistent with other decisions on Part 36, adding that allowing the application was ‘entirely compatible with a procedural code that is intended to have clear and binding effect but not at the expense of obvious injustice and the overriding objective’.