Greggs will move its self-serve food and drinks to behind the counter to stamp out shoplifting at the High Street bakery.
The company is trialling the measure at a handful of stores which, it said, are "exposed to higher levels of anti-social behaviour".
These include Whitechapel in east London which is one of five shops that will try out the new policy – the others are in Peckham and Ilford.
It is not expected that the change will be implemented across all Greggs' 2,600 bakeries in the UK, but it may be rolled out to sites where there are high levels of theft.
In 2024, shoplifting offences recorded by the police rose by 20% to 516,971, according the Office for National Statistics.
But the number of thefts recorded by retailers was far higher – for the year to last September shops saw a 3.7 million rise to 20.4 million, the British Retail Consortium (BRC) said.
Greggs said customers can expect to see its full range behind its counters but added: "The safety of our colleagues and customers remains our number one priority."
Some retailers, including supermarkets, have reported been targeted by organised gangs who wear bluetooth headsets to communicate with each other and set off alarms in stores to create a distraction allowing their fellow shoplifters to escape.
Andy Higginson, chair of sportswear and trainer retailer JD Sports and the BRC, recently told the BBC that some see shoplifting as a "way of life", allowing them to trade or sell what they have stolen.
"There is an element of society that is starting to take stealing from stores as a way of life and that needs to be stopped," he said.
