Eight bars sold alcohol to an underage person during a police test purchasing operation around Aylesbury and Buckingham.
Three double rooms were also sold to an older man and a younger female during the same operation.
The operation was carried out by Thames Valley Police in partnership with Aylesbury Vale District Council (AVDC) on July 12 and 19 which saw a plain clothes police officer, accompanied by a volunteer young person, attempt to obtain a room in a hotel and/or purchase alcohol.
The expectation is hotel or bar staff would be suspicious at an older male with a younger female attempting to book a hotel room and flag their concerns immediately to the police.
This type of operation is carried out across the country on a regular basis to make sure communication continues between hotels and the police, while educating licensed premises and encouraging better working practices.
During the operation, 16 hotels and bars were tested.
All of the premises targeted in the operation were contacted, and those who failed any aspect, were informed officers from Aylesbury Vale District Council licensing would be arranging a separate visit.
Pete Seal from AVDC licensing, said: “Working with our partners we have been actively encouraging all members of the night time economy to be professionally curious and have the confidence to say something if you see something.”
Supt Olly Wright, police commander for Aylesbury Vale, said: “The results of this test purchasing operation show valuable lessons are still to be learned. Our inability to book more hotel rooms was found to be more due to lack of availability rather than the actions of hotel staff.
“In every case where it is believed a customer attempting to buy alcohol for a person under 18 years of age, staff should ask for identification; if identification is not produced the sale should be refused.
“A joint agency scheme called Hotel Watch is being implemented across Aylesbury Vale and these operations will continue to ensure the safety of those living and working in our area.”