Fashion giant Zara has become the latest retailer to charge shoppers who return items bought online.
Customers now must pay £1.95 to return clothes, with the cost taken from their refund. Items bought online can still be returned for free in stores.
High Street firms such as Uniqlo and Next already charge for online returns.
Online shopping boomed in the pandemic, but customers are more likely to return items bought online than in store, raising costs for retailers.
Analysts said other retailers were likely to follow Zara in charging for returns.
"It's a growing trend, it started pre-pandemic and it will continue, as online shopping continues to grow," said Nick Carroll, Mintel's associate director of retail research.
Allowing free in-store returns may help drive people back into shops, Mr Carroll said.
"You also get the products back into shops quicker, which is more cost effective, and plus you have the possibility of impulse purchases once the shoppers are in the stores."
Online shopping rose strongly during the pandemic, but this has also meant a big increase in the number of items being sent back because they do not fit, or are not as expected.
For fashion retailers, returns can be costly.
Earlier this month, fast-fashion brand Boohoo said soaring returns were partly to blame for a slump in its annual profits.
Zara's decision to stop free postal returns has been criticised by some customers online.
One person wrote on Twitter: "Zara making changes to your free returns which now cost your customers and making no announcement about it? Not cool."
Another said she was "very disappointed" by the move, adding: "Expected better from you. The best, quality brands don't charge."
But another praised the decision for its environmental impact, saying it was a "great measure to help stop C02 emissions".
A spokesperson from Zara told the BBC: "Customers can return online purchases at any Zara store in the UK free of charge, which is what most customers do.
"The £1.95 fee only applies to the return of products at third party drop off points."
Legally, people have a right to claim a full refund for products that are of unsatisfactory quality, unfit for purpose or not as described, provided it is done within 30 days of ownership.
Zara aren't the first and they wont be the last big retailer to start charging for postal returns. Shops have been desperate to benefit from the boost in online sales, but none of them want the logistical headache and financial cost of processing returns.
Where a return in a shop can be processed quickly, and physically put back on a rail ready for re-sale, it's a very different picture online. Items need to be returned via a courier, sent to a warehouse, unpacked, cleaned, and then put out for re-sale, and that process is not just more expensive, but means clothes in particular may have missed their season.
There's an environmental impact of delivery vehicles making returns which many shoppers are becoming more conscious of, but pandemic habits of shopping and returning directly from your home will be hard to break without a financial hit for the customers.
The real win for the stores would be nudging the customers into not returning online items at all. Zara are hoping to strike the balance with a return price that puts the customers off a return without putting them off a purchase.