Service Bureau

office that deals with satisfying customers in a certain area and has the ability of data processing

A service bureau is a company which provides computer services for a fee. The term is no longer widely used, except for payroll service bureaus.If the services are computing facilities, not a specific business service, the service is now called utility computing. Earlier versions of this were provided by time-sharing or batch-processing service bureaus.If a specific business service is provided, this is now called software as a service. A classic example is payroll processing by a payroll service bureau.
See more at Wikipedia.org...

Noun
1. a business that makes its facilities available to others for a fee; achieves economy of scale
(synonym) service agency, service firm
(hypernym) agency