Teenagers will be sent into shops in Fife to check whether fireworks are being sold to people who are underage.
The council said it is pioneering the sting operation in Scotland
It is the first time a test purchasing scheme has been introduced in Scotland, according to the local authority.
The law currently prevents fireworks being sold to under-18s but there have been concerns at the number of young people who are able to buy them.
Supplying to minors can carry a £5,000 fine. Fireworks legally go on general sale in Scotland from Monday.
A similar scheme was used to test alcohol sales for the first time last year.
Councillor George Kay, chairman of the council's police, fire and safety committee said: "Fireworks are great fun when used and enjoyed responsibly both personally and at organised displays. But they can and do cause untold misery when abused.
"I'm pleased at the tough approach we are taking on preventing underage sales."