You can change the distance you have registered for via My 4Days. You can make the change without charge up to the end of the week before the 4Days Marches event starts. After this date, changes to the distance can only be made on Sunday 17 or Monday 18 July at the Central Administration desk at the start/finish grounds. You will need to pay a fee for this.
Please note that once the 4Days Marches has begun, you can no longer change the distance you will be walking. You must then walk the full distance you are registered for on each of the four days.