Manchester-based CTI, which won the project after a competitive pitch, will develop the site using Drupal 7.
It’s another significant London-based client for CTI, who recently picked up a web design project from London Gatwick.
Nick Rhind, CEO of CTI Digital, said: “We are looking forward to working with the Greater London Authority to provide a secure and accessible platform which can cope with unprecedented levels of traffic.
“Adding another government client to our list and working on a project of such strategic importance to London really reflects our reputation within the industry as a reliable and trustworthy long term digital partner.”
CTI Digital’s other clients include British Council, Manchester Central, Mercuri International and Travelodge.