PrettyLittleThing has introduced paperless returns to Australia and New Zealand, moving returns online.
Parent company Boohoo operates a similar model for its flagship brand across both markets.
It takes 37 trees to produce just one tonne invoice paper.
The move comes as Boohoo Group sales soared in the first half of 2020, despite global lockdowns amid COVID-19.
Customer numbers accelerated by a third to 17.4 million, and shoppers bought 10% more items per basket.
This saw half-year profits up 51%, from £45.2 million to £68.1 million ($AU 122 million) on revenues of £816.5 million ($AU1.5 billion) against £564.9 million in the prior period.
Boohoo Group has upgraded its revenue growth targets from 25% to 28%-32% for the full year.
In line with digitised returns locally, the company is investing in more automation at its Sheffield and Burnley plants in the second half as well as tech transformation initiatives.