The Charity Voucher service is run by Anglia Giving, a not-for-profit company, Limited by Guarantee, set up in 2002 specifically to run the scheme to encourage charitable donations. See About Us.
Anglia Giving is not a Registered Charity because it’s purpose is fund-raising for Registered Charities and it does not have its own specific ‘charitable purpose’, i.e. a particular cause it raises money for. This would probably be required by the Charity Commission in order to be able to register as a charity.
Instead, the organisation is formally constituted as a not-for-profit, social enterprise company (belonging to the National Council for Voluntary Organisations – NCVO and also to Social Enterprise UK).
Any surplus funds, after covering operating costs, are used to improve aspects of our service or else are donated UK charities.