A Didcot Parkway - Swindon off-peak day return is £14.80, but the equivalent (avoiding Reading) from Oxford is £13.40. In both cases the earliest it's possible to arrive at Swindon is 09:55, so why does the anomaly exist? Are there any other similar situations?
I am not going to post more than one example because the most common outcome is for the cheaper fare to be increased.
In this case there is a real risk of Swindon to Didcot going up in price; the outcome will be to encourage people onto the direct bus service but GWR would probably rather lose out on custom on that flow to the bus than lose revenue from people making the shorter journey for which they charge a premium fare, and starting or finishing short with the Oxford ticket.
So the example I will post is Brighton to Southampton route Not via London is valid via Clapham Junction but is cheaper than Clapham Junction to Southampton.
I am only posting this as it has been widely publicised and both the price and routeing appear to be protected (unless/until fares reform allows prices to rise) and so the train companies cannot do anything about it.
Any other examples could see prices rise which would be very bad for the customers who actually make those journeys, as they will either have to pay more for their journeys or be forced onto other transport modes or simply make fewer journeys.
It is very common. If there is one fare per reply the thread will run for hundreds of pages.
It would be like a gold mine for pricing managers!