Wix domains with a .co.uk suffix require a change of the TAG Name in order to transfer them away from Wix.

Important:
When submitting your request, make sure you are signed in to the Wix account associated with the domain you want to transfer.
You must cancel your Wix domain before submitting a request to transfer away your .co.uk domain.
In order for WIX to perform the transfer, click here to submit a ticket and include the following information:
Wix username
TAG name of the new domain host (NAMECHEAP-INC)
Wix domain name