LONDON, May 6 (Reuters) - British employers had registered 4.2 million jobs as being on furlough on March 31, down from 4.7 million on Feb. 28, provisional tax office data showed on Thursday. The total number of jobs on furlough peaked at 8.9 million in May 2020 and fell as low as 2.4 million in October, before the government reimposed lockdown restrictions. (Reporting by David Milliken; Editing by Alistair Smout) Our Standards: The Thomson Reuters Trust Principles.