CrossCountry are offering a 25% discount on their Advance Purchase fares, in both Standard and First Class until 31st May 2011. The discount is available for journeys after that date so long as they are booked before 31st May. The promotional offer page of their website appears to suggest that the offer is only available on journeys to/from Newcastle, but I've checked various journeys across the CrossCountry network and all appear to offer the 25% discount.
Booking from the promotion page automatically includes the 25% discount. Alternatively you can book from the CrossCountry homepage and enter 'OFFER25' in the 'Promotion Code' box under 'Journey Options'.
The offer appears only to work on journeys wholly with CrossCountry, so doesn't include '
XC▸ & Connections' AP fares.
Cumulative discount for Railcard holders.
http://www.crosscountrytrains.co.uk/offer25/ EDIT NOTE: The T&Cs on the XC website make no mention of the end date being 31st May, but I'm reliably informed by someone who has seen printed promotional material that this is the case.