The pre-action protocols cater for a number of closely circumscribed causes of action, none of which are likely to arise from a a ticket validity dispute. However, the Practice Direction as to Pre-action Conduct
is pertinent to prospective civil proceedings arising from such a dispute it can be found at
https://www.justice.gov.uk/courts/procedure-rules/civil/rules/pd_pre-action_conduct. Note, in particular Paragraph 13:
"If a dispute proceeds to litigation, the court will expect the parties to have complied with a relevant pre-action protocol or this Practice Direction.
The court will take into account non-compliance when giving directions for the management of proceedings (see CPR 3.1(4) to (6)) and
when making orders for costs (see CPR 44.3(5)(a)). The court will consider whether all parties have complied in substance with the terms of the relevant pre-action protocol or this Practice Direction and is not likely to be concerned with minor or technical infringements, especially when the matter is urgent (for example an application for an injunction)." [My emphasis]
Failure to engage with a prospective claimant who observes the PD's requirements may render the defendant vulnerable to a costs penalty. Correspondingly, a defendant's failure to respond to a properly framed Letter of Claim may provide a claimant with a shield against an adverse costs award even if his claim should fail.
Hilariously, the learned panel of Judges who authored the Handbook for LiP's observe that "The pre-action protocols are high-minded, very lengthy, over complicated and, essentially, counter-productive" before going on to say that you should still follow them. Now there's a vote of confidence in the Civil Procedure Rules regime for you! From the costs perspective they are, nonetheless, a useful weapon in the litigants armoury.
You should also beware of the fact that the Handbook was writen in 2013. Since then, the hourly rate of costs that may be allowed to LiP's unable to prove a greater level of loss appears to have risen to £19.00 see CPR PD 46 para. 3.4. The handbook's text may be out of date in other respects.