TNT Post, which is owned by PostNL, will handle a number of projects for Tesco including the mailings for all customer communications from Tesco Clubcard and Tesco Bank.
The Clubcard scheme alone sends several mailings a year to more than 15 million households.
TNT Post claims it won the contract following a competitive tender with chief executive Nick Wells attributing the win to "robust operational capability, excellent customer service and value for money".
TNT's client roster already includes Barclays, BT, Centrica, Lloyds TSB, nPower, Sky and E.ON.
In addition TNT Post said it would run test postal deliveries to homes and businesses in West London from mid-April after a previous trial in Liverpool.
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