So I went on coinatmradar and there is an available atm to buy or sell at 'Skunk House' in Croydon. Sounds a delightful venue to conduct financial transactions.
https://coinatmradar.com/bitcoin_atm/924/bitcoin-atm-lamassu-croydon-skunk-house-croydon/
Thanks. I will buy some more. There's a number of cafes and restaurant near me where I can use Bitcoins.