How to buy a Priv-rate ticket, and what to do if this is not possible
At present it is not possible to buy Priv-rate tickets online, by phone, or from ticket machine
Where the station has a staffed ticket office, you must purchase a valid ticket before you start a journey, irrespective of the length of queue or wait time.
If the ticket office is closed and local ‘promise to pay’ tickets are available from vending machines you must obtain one before travelling.
If you board a train from a station with an open ticket office and have no ticket, or from a station where ‘promise to pay’ tickets are in use and you haven’t obtained a ‘promise to pay’, the train operator is within their right to refuse to sell you a Priv-rate ticket and report it as a Travel Irregularity.
Only if the ticket office is closed, and there is no local ‘promise to pay’ in use, can you buy a Priv-rate ticket on board a train. You must actively seek out staff on-board the train, have your fare ready and offer to pay it at the first available opportunity. By offering to pay there can be no question that you are trying to travel without paying.