Marks & Spencer has extended its Mobile Pay Go service to 50 branches, mainly in London, following a successful trial in six stores.

M&S said the checkout-less technology, which enables transactions to be processed in less than 40 seconds, has handled purchases once every three seconds during busy lunchtimes in pilot stores.

The scheme is now being introduced in shops which are particularly busy during daily peak periods. The retailer said its deployment will enable staff to provide enhanced service and slash queuing times.

Marks & Spencer retail, operations and property director Sacha Berendji said: “M&S is changing to become a digital first retailer with industry-leading store operations and Mobile Pay Go is a really exciting part of that.

“Today’s rollout means more of our customers will be able to benefit and enjoy a seamless shopping experience, which we know is especially important at lunchtime.”

Joe Erskine, store manager at Marks & Spencer’s Clapham Junction shop, which has been using Mobile Pay Go since the branch was revamped last year, said: “We all know how fast-paced London life is and how busy our customers are, so the great response we’ve had to Mobile Pay Go has been no surprise. Making it as easy as possible for customers to come in, purchase our products and be on their way is hugely important to us.”

Only members of M&S’s Sparks loyalty programme can use the payment app, which enables them to scan products up to the value of £30 and click to pay without queuing.