If you have other services with us, then you will have an account, which is where you manage all your services, domain names and billing.
Login at clients.zenmsp.uk
If you do not have an account or any other services with us (ex Loudex customers), then you most likely have an enom sub account. In which case please login at enomcentral.com
If you have lost your login details, please use the "forgot password" and "forgot login" links on the login page.