Can I transfer my race number to someone else?

Not without the organiser's permission. Under UKA Rule TR5 S2(3), numbers are issued to the individual runner who completed the entry form, unless the competition provider specifically authorises a transfer.

• Runners who use a transferred number without permission are disqualified.
• Both runners (the one who gave the number away and the one who used it) are liable to disciplinary action by their home country athletics federation.

Other bib rules for road races:

• Wear your bib visibly, normally on the front of your body.
• The back of the bib should have space for medical information and contact details, which you fill in before the race.
• You must retire immediately if ordered to by a race medical officer.
• If you retire, don't remove your bib until you have reported to an official that you've retired.