Retailers have been caught selling cigarettes to under-age teenagers in an undercover investigation in South Gloucestershire.
Five of the 21 outlets visited sold cigarettes to 14-year-olds volunteering for Trading Standards officers operating in the area.
The other 16 outlets refused to sell to the teenagers.
Further action is now being considered against the businesses where the sales occurred and against staff concerned.
Retailers found guilty of selling to under-16s can be fined up to £2,500.
Shirley Potts, of South Gloucestershire Council said: "We will continue to use under-age sales checks and retailers should be aware that any infringements may result in court action."
"We are also encouraging parents and the public to help by letting us know when they suspect underage sales are being made to youngsters."