On Azure’s status page, Microsoft’s messages have linked the outage to an “inadvertent configuration change” and DNS problem. At around 3:20PM ET, the company said it had finished deploying its “last known good” configuration and says customers should soon start seeing signs of recovery, with “full mitigation” expected in the next four hours.

On outage monitoring site DownDetector, issues have been reported with Xbox, BT, NatWest, O2, John Lewis and Amazon, amongst others.

Microsoft saw its Azure cloud business grow 40% in the September quarter, above the 38% rate analysts were expecting, and in line with the 40% "whisper" number on Wall Street.