A screen half the length of a football pitch, wrapped around London's BT Tower, will display live updates from England's World Cup matches.
The information, on a 360-degree LED screen measuring 60m (197ft) in circumference, will be visible for miles from the tower in Fitzrovia.
BT said screens in its call centres would allow staff to watch the football matches during office time.
England's first match is on Saturday against the United States.
The screen - made up of more than half a million lights - will display messages like "Come on England" in addition to live scores.
England's scores will be displayed on a red background with 3.6m (12ft) long white lettering, while for updates for the US will be in blue.
The updates, displayed on the screen which stands 170m (550ft) above the ground, will be visible from South Bank and Primrose Hill.
The World Cup kicked off in South Africa earlier.