Doesn't British consumer law forbid the addition of restrictive clauses after the transaction? So the extra restriction printed on the ticket (requirement for the number to match) is only applicable if the purchaser is advised of it beforehand. It would need to be in the published t&c of the TOC (or NCRoT),
Well there are still neither posters at stations nor (easily-implemented) buttons on touch-screen TVMs for displaying a copy of the NRCoT - and see how much trouble it causes even asking for a copy at a ticket office nowadays! A walk-up purchaser is rarely offered access to the T&Cs of the contract at the time of purchase.