Holders of most Standard class tickets can upgrade to the added comfort of First Class on selected train companies on Saturdays, Sundays and Bank Holidays on trains which convey First Class accommodation. Sometimes, trains have designated "Weekend First" coaches which are clearly labelled.
You can upgrade on the train - on a first come, first served basis. On some services, you may be able to reserve a seat in advance. If you have a seat reservation and miss your selected service, you can still use it on another service for the same journey on the same date at no extra charge, as long as you're not travelling on an Advance ticket.
Participating train companies: CrossCountry, East Midland Railways, Great Western Railway, Greater Anglia, LNER, ScotRail, South Western Railways, TransPennie Express and West Midlands Railway.