Charity shops say they are having to get rid of changing rooms and sell items online as they lose thousands of pounds to a rise in shoplifting.
Figures show shoplifting in Wales is at its highest level in more than 20 years.
There was a 36% increase recorded by police forces in Wales from September 2022 to September 2023, compared with a 32% rise in England, ONS data showed.
One former shoplifter said sentences given were not enough of a deterrent.
Jenny Langley, who oversees more than 50 charity shops for Tenovus Cancer Care, said some people were stealing through necessity because they did not have "any clothes to put on their child".
But she added most were organised criminals looking to make a profit.
"Every day the staff will find empty hangers where something has been taken," she told the BBC Wales Live programme.
Debbie Russell, a charity shop volunteer who recently had to stop a woman walking out with clothes hidden under a pram, said it prompted "a range of emotions".
"It's sadness that people feel it's OK to steal from a charity, it just feels really wrong," she said.
The charity estimates it could be losing £87,000 a year to shoplifting and said many high-value donated items now had to be sold online.
Former shoplifter Cullan Mais, 32, from Cardiff, said current prison sentences were not enough of a deterrent.
He was imprisoned 10 times after stealing to fund his drug addiction and believes others like him find it easier to justify to themselves than mugging or burglary.
"As bizarre as it sounds, there is that moral compass in people's minds," said Mr Mais, who now works for a substance misuse charity.
He added the increase was likely partially down to the cost of living crisis, as more people would be willing to buy from shoplifters.
"I've had people come to me and say 'I wish you were still shoplifting' because they are struggling," he said.
Mr Mais added shoplifting was addictive and he had recognised "trigger moments" himself since stopping, such as seeing certain goods or hearing Christmas music in a store.
In the year to September 2023, there were 21,640 recorded shoplifting offences across Wales, compared to to 15,939 the previous year.
Meanwhile in England, there were 378,127 and 287,015 in the years to September 2023 and September 2022 respectively.
Filco supermarkets, based in south Wales, has installed a new security system using AI, after being targeted multiple times a day by shoplifters.
"It can make a perfectly profitable business question whether they can actually continue," said Matthew Hunt, the company's director.
He said thefts by shoplifting peaked for them between August and October last year, with some individuals taking thousands of pounds worth of goods per day.
"I'm aware of other retailers who have, and are close to, the decision to close their business on the basis that they can't deal with theft. They feel they don't get the support from authorities and feel there is little they can do to protect themselves.
"It's really sad."
Mr Hunt felt he had to invest heavily in security, to protect his staff and business.
A new CCTV system, installed across the chain's stores, uses artificial intelligence to recognise when someone is stealing, while facial recognition software flags known shoplifters to staff the moment they enter a store.
"It can spot things like putting meat inside your jacket or filling up a rucksack," he said.
"It then sends us a short clip that we can view in real time while that person is still in the store."
Steve Rosser, Filco's security manager, said shoplifters often had "nothing to lose" and more were starting to carry weapons, including screwdrivers and syringes.
"We went after someone who had bagged up a load of meat," he said.
"They pulled out a needle from their trouser waistband and uncapped it. That was enough for me to put my hands up and just say 'go, just go'.
"I felt like I'd failed in my job. It actually made me question whether this was the right industry to work in."
Gwent Police saw the highest rise in shoplifting offences among Wales' forces, with a 52% increase between September 2023 and the previous year.
Supt Jason White said in Newport, shoplifting was accounting for 10% of all crime, prompting a new operation designed to target prolific shoplifters in the city.
"Most of our offenders have some sort of ailments like drug or alcohol dependency or learning difficulties," said Ch Insp Amanda Thomas.
"They are not offending because they want to. There is a reason behind the offending, and we need to find out what that is."
You can watch more of this story on BBC Wales Live, available on iPlayer