It broke out at Lloyds, in Market Walk, at around 6.30pm yesterday.
Two fire engines from Tiverton initially attended. On arrival they then requested a third fire appliance from Cullompton because of a large amount of smoke.
Fire crews forced entry into the property and discovered that around half of the ground floor was damaged by fire and the remainder of the ground floor was severely damaged by smoke. The first floor was also slightly damaged by smoke.
Initital reports suggest the fire was accidental.