Tesco and Waitrose have become the first UK retailers to begin trialling Apple's iBeacon technology.
Apple's iBeacon technology enables retailers' apps to detect when an iPhone with the app installed is nearby. The iBeacon – a small wireless sensor – can then send special offers and notifications to the user's iPhone.
Tesco started a trial of the technology at its Chelmsford store last month, while Waitrose kicked off its own testing last week in Swindon.
Waitrose is using the tech with its app to send price promotions to iPhone users while shopping in the Swindon store.
The app will also allow shoppers to scan products. They can then choose to read reviews of the product, add items to a shopping basket and then pay for the goods via the phone.
Tesco has said that it will avoid using the technology for marketing to its customers for the time being. It said it isn't sure UK shoppers are quite ready to be marketed to in that way.
Instead, it is planning to use the technology to prompt shoppers when their pre-ordered goods are ready.