You don't need to let us know if you want to change trains, but you'll need to check the terms of your ticket to see if it'll still be valid for a different train.
I've booked an Advance ticket
I've booked an Off-Peak or a Super Off-Peak ticket
I've booked an Anytime ticket
If you need help knowing whether your train is Off-Peak, Peak or Super Off-Peak just put your journey into our train times page and we'll do the rest.