Tesco has become the first major supermarket to try phasing out 5p single-use carrier bags, meaning shoppers who don't take their own to store will have to buy bags for life.
The retailer has launched the 10-week trial in its Aberdeen, Dundee and Norwich stores and if successful, it could scrap single-use bags.
Laws introduced in England in October 2015 forced larger retailers to apply a 5p charge to flimsy single-use carriers - a scheme already in place in Scotland, Wales and Northern Ireland.
Bags for life are made from a thicker plastic and cost 8p and 10p.
The supermarket said that online customers will still have the option of buying 5p carriers to have their shopping delivered in - but 57% now choose bagless deliveries.
Official figures released last July showed an 85% drop in the number of single-use bags used by shoppers once the charge was introduced.
As well as being designed to benefit the environment by reducing the amount of plastic in circulation, retailers are expected to donate the 5p charge for bags to good causes.
Tesco told ITV News its Bags of Help scheme, which supports local groups as chosen by customers, will continue using profits from bags for life.