Evening guys.
I've received a reply from the site team and I've copied it below, Maybe Syzzie can shed some light later on this kind of stuff:
Hi Leslie,
Thanks for your email.
Sorry to hear your donors have had difficulty making a donation. The possible reasons for the donation being unsuccessful are:
Their Internet browser - some internet browser's don't support our website and they may need to use a different browser for example Internet Explorer or Firefox
Firewall security - We recommend that they use a personal PC rather than a work/public PC as the firewall may prevent the payment being completed
Postcode - Although the postcode field is marked with an * if they don't have a valid UK postcode please leave this blank.
Cookies/history - please clear these as they may stop you accessing parts of our site, also make sure that the cookies are turned on.
I would ask them to attempt the donation again going through the I'm not registered route and if you have any further issues contact a member of our team on 08456 10 10 45 and we will go through this process with them.
Kind Regards,
Chelsea