Daresbury-based Converge Technology Specialists has won its first £1m contract after signing a deal with East of England law firm Bridge McFarland.
The company will provide a cloud service to the firm, which has 21 partners and offices in Yorkshire, Lincolnshire, and London, over the next five years.
Bridge McFarland's managing partner Richard Parnell said: "Looking forward, we want an IT system that is resilient, and to work with Converge in partnership."
Nigel Wright, managing director of ConvergeTS, added: "The cloud is the future for the legal industry and as the only provider dedicated to law firms; we are in a prime position to expand our reach."
ConvergeTS invested £800,000 in new premises in Daresbury Park in 2014, helped by a £160,000 Business Growth Grant from the Liverpool City Region Local Enterprise Partnership.