Below  is a copy of the Sponsorship  Form  (but it doesn't appear to be complete)

Suggest you print it out and send it WITH YOUR DONATION  to :=

Philip Tomes
Wiltshire Air Ambulance Appeal
C/O Salisbury Library
Market Place
Salisbury
Wiltshire
SP1 1BL

Please make out a cheque etc to :-

Wiltshire Air Ambulance Appeal

N.B. You do not appear to be able to make an online donation using your PLASTIC

To use the GiftAid , to make to donation more tax  efficient, do this....

Log onto their website,  http://www.wiltshireairambulance.co.uk/donate.htm  and download the complete form .
Follow the " Make a Donation" links, PRINT the form,, WRITE the cheque and the send it to Philip a the above address..
 
This has a data protection option as well.