Using the online booking system, which went nationwide last week, staff input their home postcode, how far they can travel and their availability. Managers can then see who is available nearby and book them for shifts up to six weeks in advance. Staff will be informed of their shifts by email or text message.
Until now, overtime has been booked manually by line managers approaching people in-store or by staff signing themselves up for additional hours on staff noticeboards, sometimes with just a week's notice.
Guaranteeing sufficient staff to work late nights and Saturday evenings was one of the biggest issues Tesco faced, said flexibility programme manager Arnie Herrema. "This will give us an opportunity to ensure we're properly staffed at those times," he said.
Staff can use computers at work or at home to register their availability, or call a freephone number. More than 4,000 people have signed up following last week's training workshops.
"Staff can now plan their time much more productively," said Herrema, a former store manager. "It gives them a better work-life balance so they won't feel pressured at short notice into doing overtime."
Tesco plans to phase out manual overtime booking next year.