The move is part of Busk in London, an initiative to encourage performance across public spaces, backed by the Metropolitan Police, Network Rail, Transport for London and London boroughs, as well as Ticketmaster.
The scheme includes buskinlondon.com, a website which helps people get information on London street music and identify busking locations across the city.
The winner of Gigs will perform at the grand final at Westfield Stratford City in September, with prizes including a licence to busk on the Tube, a busking trip to Paris, music college courses, recording sessions and coaching from professional songwriters.
For more information and how to enter visit london.gov.uk/gigs