Staff at Waitrose’s Surbiton branch are being driven ding-dong by the incessant beeping sound made by hand-held Deliveroo order terminals.

Now customers have joined the chorus of complaints about the Sunmi point-of-sale devices that emit the repetitive ear-piercing four-note ringtone every few seconds.

As staff go round the aisles, filling baskets for home deliveries, the beeping goes with them. “It’s really annoying,” one admitted. “It’s still in my head after work.”

When shopper Bob Helliwell complained, he was told: “We’ve had a lot of comments; it drives us mad too.”

Waitrose head office told The Good Life that the sound “alerts partners to new orders”, insisted nobody had raised the issue and said it merely sounded like a mobile phone tone.

Surbiton was the third Waitrose to trial the Deliveroo tie-up.