You stated in your answer that RO was liable as he hadn't received a DVLA acknowledgement letter (or chased them for it). There is no basis whatsoever in statute for the DVLA's acknowledgement letters, nor any requirement to chase the DVLA for not receiving them. The DVLA has admitted this in correspondence. Indeed, the actual wording on the V5C is ambiguous, as it can be read that you should complain (on their expensive telephone number) if you receive a letter before 4 weeks have elapsed. To take the legal arguments a step further: 1. The Universal Postal Union (of which UK is a signatory) makes it absolutely clear that, in the UK, post becomes the property of the recipient at the moment that it is committed to the Royal Mail. 2. The Interpretation Act 1997 s.7 makes it absolutely clear that a document sent by first class post is deemed served. So provided that the sender has proof of posting (or a witness), the DVLA's letter of acknowledgement is a mere distraction. If he has no proof, then he can swear an affidavit that the V5 was completed and posted. I am not aware of any case, which has been challenged as above that has been taken as far as the Magistrates' Court by DVLA