I'm wondering about what to do about Tax issues, as I have some pretty big domain transfers coming up, and am wondering if domain sales are taxable in the UK.

I've never really looked into it, as the domains I've sold previously haven't amounted to that much.

Since domains are 'rented', you are not really selling goods (or a service), just transferring a rental period over to someone. Furthermore, you never really owned anything in the first place, so the domain is 'transient'.

Can any UK legal beagles advise?