Callcredit will also host the database and its Interaction Centre will handle all subscription-related customer communications.
These include both online and offline consumer contacts for new subscriptions, enquiries and renewals, utilising both trained customer advisers and a specifically designed front end website.
Kai Muxlow, newspaper sales manager at The Guardian, said: "Callcredit has a great deal of experience in managing subscription services and we are looking forward to developing a successful partnership with them."