The cryptocurrency hole-in-the-walls are set to come to the capital next month, but the competing companies have yet to disclose the exact locations.
The firms are now waiting on the completed machines to arrive from manufacturers Lamassu and Robocoin, according to CoinDesk, after three Canadian cities had Bitcoin ATMs installed last week.
Robocoin ATMS enable two-way conversions between fiat currency and Bitcoin, and are able to identify a user via a biometric reader.
Global Bitcoin ATM is considered to have the most ambitious plans, with spokesperson Terry James telling CoinDesk it will install five machines a month in London.
He said: "We think there's a niche for people who want to get involved [in bitcoin ATM ownership] but don't have the time or resources."
The firm would run the machines on behalf of their owners.
The other forerunners include Satoshipoint, which has two Robocoin machines on the way, to be installed at bureau de change in Oxford Street and Notting Hill - but only by March.
Meanwhile, entrepreneur Joel Raziel said he has found an east London location for his $5,000 machine.
Satoshipoint would charge users between 3% and 5% per transaction, but the others have not yet revealed their fees.
The UK has no specific laws to govern Bitcoin cashpoints in the UK.