Under Mallzee's Lost Stock initiative, boxes of clothes - with brand labels removed - are sold for 35 pounds ($44), with 37% of the retail price donated to a charity supplying food and other goods to clothing workers hit by layoffs and unpaid wages.
"We had the industry contacts to be in the perfect position to connect consumers with the cancelled stock supporting garment workers and helping avoid the clothes ending up in landfill," Melanie Gray, a spokeswoman for Edinburgh-based Mallzee, said.
Labour advocates in Bangladesh welcomed Mallzee's efforts but expressed concern that such initiatives could let big brands off the hook over mass cancelled orders that are putting the livelihoods of thousands of workers at risk.
"I appreciate this. But why do our workers have to live on charity?" Kalpona Akter, founder of the Bangladesh Centre for Worker Solidarity, told the Thomson Reuters Foundation.
"It will be highly appreciated if they (Mallzee) can pressurise brands and ensure that they pay up."
Millions of Bangladeshi households depend on the garment sector, which has been hit hard by the pandemic. Exports fell by 84% in the first half of April as $3 billion-worth of orders were cancelled or suspended, according to factory owners.
As the industry reels from the blow, Rubana Huq, president of the Bangladesh garment manufacturers and exporters association, said schemes like Lost Stock were "imperative."
Last week, Bangladeshi manufacturers said they would blacklist Western fashion brands that "exploit" them by failing to pay their bills due to the coronavirus crisis, days after threatening to sue a major British retailer over its debts.
Several manufacturers have struggled to clear workers' dues in the last two months due to the cancellations, and hundreds of unpaid garment workers protested on the streets last month.
Since launching the programme two weeks ago, Mallzee has sold 80,000 boxes of clothes, far exceeding its goal to sell 10,000, Gray said.
She said the company had collected enough funds to supply parcels of food and sanitary products to help 80,000 garment workers and their families.
Mallzee is working in partnership with Sajida Foundation, a Bangladeshi NGO, which plans to begin the distribution of the aid packages next month.
"We're in the process of making a list of garment workers who need the relief. It can support them for two months," said Muhymin Chowdhury, spokesman for Sajida Foundation.
Researchers say charitable efforts will not be enough to support workers in the longer term, urging the government to work with factory owners to create a social safety net for garment industry employees.