Blow to NHS as Royal Mail raises prices for bulk users by a third

The tariff increases will affect Royal Mail’s bulk mail customers such as UK Mail, Whistl and Citipost, which sort and process mail on behalf of big businesses. Photograph: Rui Vieira/PA

Royal Mail will increase the price of its wholesale postal service by as much as a third, in a multimillion-pound blow to the NHS and other large organisations.

The postal company has warned customers who use its wholesale postal service for mail including marketing letters, household bills and medical appointment notices that it is raising prices by an average of 25% from 5 October.