The Royal Borough of Greenwich successfully prosecuted Repairs 4 Mobile, on Eltham High Street, and its director, Hassam Zia, for selling mislabelled vapes.
Some of these vapes featured unauthorised trademarks of sweet brands and cartoon-style images of fruit-based characters.
Mr Zia pleaded guilty to the offences at Bromley Magistrates Court on March 26.
The business was visited several times by the council following complaints from residents, starting in April 2022.
Guidance on legal selling practices was provided, yet in July 2022, 603 illegal vapes were still found on sale and seized.
Councillor Rachel Taggart-Ryan, cabinet member for community safety and enforcement, said: “This fine is a great outcome and sends a message of the council’s no-tolerance approach to the sale of illegal vapes.
“These vapes were clearly marketed towards minors, which is completely unacceptable and dangerous, so the fine reflects the seriousness of the offence.
“We will continue to take the necessary steps to ensure our residents are safe and feel safer, especially when it comes to prosecuting traders that market dangerous products so deliberately to children and young people.
“We hope this substantial fine sends a message to anyone seeking to trade harmful goods in our borough.”
Mr Zia and the company were each fined £2,500, with victim compensation charges of £1,000 and costs of £5,129, totalling £17,258 to be paid between the company and director.
Mr Zia said that he had been experiencing medical problems, and his staff had been selling these vapes without his permission.