On National Express, tickets can be amended by clicking here or calling National Express on 03717 818181 or +44 3717 818181 from overseas.
You can also amend your ticket at over 2,000 agencies, click here for a list. Opening hours of these outlets vary.
An amendment fee will apply so please have your credit/debit card details to hand. Please note that an excess fare will also be charged where a higher fare category applies.