With the old ticketing system if there was no first class fare showing for a journey then you could create one by taking the standard day or standard return price and adding 50%. This was helpful as it meant you did not need to have fares in the system for little journeys where there might only be one train a day and the demand would not be that high for a first class fare. It also helped to cut down the size of the paper based fares manual.
The old ticket issuing system did not have a problem with this as the memory of the machines was low so many fares prices had to be entered manually. Of course mistakes could then be made and tickets could be issued for the incorrect price. Management did not like this especially if the ticket was sold for a lower price.
ATOC» had a department that would invoice the
TOC▸ invloved for the difference so the TOC would lose money.
When the ticket machines were upgraded (on train from sportis to advantix) it was decided that if a fare was not in the system then you could not issue it. So now you have the situation that if a first class fare does not exists then you can not sell it.
What usually happens is that someone finds out about this for a particular journey - starts travelling first and offering to upgrade knowing full well there is no such ticket. On train staff will then feedback to their managers and in the next fares round a first class fare will be created for that journey. Quite often then the passenger will stop making the journey