Police and Trading Standards in Swansea are urging licensed premises to check young people for ID when selling alcohol to them.
The call comes after a test purchase exercise carried out at the beginning of the month resulted in some of the businesses selling alcohol to 16-year-old volunteers.
Two of the nine premises visited supplied alcohol to the youths without any challenge of their age.
Martin Saville, Head of Environmental Health Services in Swansea Council, said: “We are aware of the amount of disruption that the misuse of alcohol causes within local communities and we will make retailers who are negligent in supplying drinks to minors responsible for their actions.”
Acting Chief Inspector Nigel Whitehouse said: “Our strong stance on the sale of alcohol to the underage continues. It was pleasing to see the vast majority of licence holders adhered to the law. However those that have flouted legislation have rightly been prosecuted.
“We will continue such operations across the Swansea authority and those licensees who sell alcohol to the young will be targeted and prosecuted.”
During the last 12 months 126 test purchases have been undertaken during 10 different exercises. Thirty sales have been made that have resulted in a variety of different enforcement actions including the issue of fixed penalty notices to staff responsible for the sales and warnings, cautions or prosecution of the business where the sale was made.
Licensed premises are also being subjected to a licence review when it becomes evident that the business is not being managed effectively.
Mr Saville added: “Recent changes in the law mean that if two illegal sales are made within three months then magistrates can be asked to suspend the licence for a period up to 48 hours preventing alcohol being sold from that premises.
“We fully intend to use this power to improve the manner in which premises selling alcohol are managed.”