Amazon will start selling the technology behind its cashierless Amazon Go stores to rival retailers, according to Reuters.

The e-commerce giant reportedly has several retailers already signed up to use the system, which is being marketed as Just Walk Out technology.

The company's cashierless system uses a combination of ceiling-mounted cameras and shelf-weight sensors to automatically track customers and items as they move around a store.

Once someone has finished their shopping, they can walk out of the store without needing to scan anything or interact with a cashier. Their account will be automatically billed, and a receipt will be emailed to them.

Amazon launched its first cashierless store back in December 2016, and now operates around 26 locations across the US, including its first traditional grocery store that it opened last month.

According to Reuters, the version of the system that Amazon is selling to other retailers will work slightly differently from the system in its own locations.

Rather than scanning an app, customers will instead insert a credit card into a gated turnstile at the shop’s entrance. These turnstiles are set to be Amazon-branded, but otherwise each location will be branded by its individual retailer.

The e-commerce giant will also install ceiling-mounted cameras and shelf-weight sensors at each location, according to Reuters, and Amazon says it takes a few weeks to install the technology in a store.