Mr Fouad Choaibi runs his mobile phone repair business from a repurposed telephone booth in central London.
Mr Umar Khalid's coffee shop in Hampstead Heath is within a similar structure.
They are part of a concerted effort to save Britain's classic red telephone boxes, which might disappear forever owing to the rise in mobile phone usage.
Often abandoned, vandalised or reeking of urine, some have been transformed into libraries, art galleries, shops and even heart defibrillator points, reported Agence France-Presse.
From a peak of 92,000 across Britain in 2002, the number of phone boxes is down to 42,000, of which 7,000 are the iconic red ones.
British telecoms giant BT is trying to keep the heritage alive with its Adopt a Kiosk scheme, which allows local bodies to buy the phone booths for £1 (S$1.80) to give them a new lease of life.