east coast
https://www.virgintrainseastcoast.co...als/halfprice/
cross country
https://www.crosscountrytrains.co.uk/birthday
20,000 discount codes available on a first come, first served basis. Sign-up required on 2 Nov 2017. Tickets can be bought between 3-6 Nov 2017 (inclusive) for travel between 3 Nov and 14 Dec 2017. Discounts apply to Standard CrossCountry Advance tickets purchased through the CrossCountry website (desktop or mobile only), subject to availability. Maximum of eight tickets can be purchased in one transaction. Discount cannot be used in conjunction with Railcards.
This is a subject that has been highlighted many times as a way of saving money on train journeys. I've heard that this usually applies to journeys involving more than one TOC.
I'm going to Glasgow in May and found that the advance ticket on the direct train with a railcard was around £43.00. I then looked at Euston to Preston and then on to Glasgow to find that the total came to around £35.00. That means my first 3 or 4 Wetherspoon pints will be free!
Virgin WC seem to be ramping up the price of tickets from London to North of the W Midlands (away from the competition) but not necessarily on the way back. What the casual rail traveller makes of all this nonsense is anyone's guess!
I have split tickets a few times and saved a fair amount. When you try to explain it to someone who doesn't use trains they look at you as if you have gone mad!
I have split tickets at York for my next trip up to Sunderland.
The other advantage to splitting is that you can give yourself a little time to have a couple of beers en route!