Four fire engines and 21 firefighters and officers were called to a fire at a bank with flats about in Seven Sisters Road in Finsbury Park.
Approximately eight square metres of the external facia was damaged by fire.
Ten people left the flats above the bank before the arrival of the Brigade. One woman was treated at the scene by firefighters for smoke inhalation.
The Brigade was called at 0112 and the fire was under control at 0306. Fire crews from Holloway, Stoke Newington, Islington and Kentish Town fire stations attended the scene.
The cause of the fire is under investigation.