The service, which the firm claims is up to 10% cheaper than Royal Mail's Mailsort 2, is for mailings of more than 4,000 items.

"It will also has the same kind of sortation levels as Mailsort, so there are 120, 700 and 1,200 services," said mailplus general manager Jon Wilkins. "As a result, it's very easy for users to switch."

Smethwick, West Midlands-based mailplus' two-day offering sits between first and second class. "If you're using second class, now for a very similar price you can get it there a day faster, so production facilities get an extra day," said Wilkins.

Mailplus uses sister firm Parceline's network of 1,704 vehicles to collect pre-sorted mail and take it to Parceline's West Midlands "superhub". It is automatically sorted and then delivered to one of the Royal Mail's 69 delivery centres around the UK for "final mile" delivery, enabling it to offer 100% UK coverage.

"We're the only downstream service that's really offering automated sortation," said Wilkins. "It means we have a far lower level of errors than Royal Mail."

The automated system used by Parceline allows mailplus customers to track their mail online.

The service was officially launched at last week's Mail Show, held at Olympia in London. Wilkins is targeting both DM and transactional clients and mailing houses directly. "If mailing houses and printers can offer their clients a premier service then that can be a differentiator."

Geopost UK is owned by France's national postal service La Poste.