City Lifeline has teamed up with 01 Telecom in a three-year deal to operate its network hardware from City Lifeline's London data centre.
01 Telecom said the deal would provide secure and reliable UC services including Hosted PBX for users.
Jon Lamont, services manager at 01 Telecom, said City Lifeline's pricing made it the ideal place to house the equipment.
"The benefits of Unified Communications and Hosted PBX are being recognised on a global scale and this has rapidly increased our customer base," he added
Roger Keenan, managing director at City Lifeline, said: "01 Telecom's growing roster of multinational clients demands a data centre that has the flexibility to be able to adapt to, not just their changing requirements, but also the requests of their clients.
01 Telecom, founded in 2009, delivers a range of hosted Unified Communications services including Hosted PBX to businesses worldwide.