The company said the impact of coronavirus on trading meant it had to make a "difficult decision". Pret said it needed to reduce headcount across its UK shops to "reflect lower footfall, rental costs and new safety measures". It did not say how many jobs would go, but a source confirmed more than 1,000. About 330 jobs will be lost with the closure of the 30 shops. Pret said 339 of its 410 shops have so far reopened following the easing of lockdown restrictions.
But trading remains slow, with sales down 74% from a year earlier, the company said. Pret is thought to be losing about £20m a month.
Chief executive Pano Christou said: "It's a sad day for the whole Pret family, and I'm devastated that we will be losing so many employees. But we must make these changes to adapt to the new retail environment.
"Our goal now is to bring Pret to more people, through different channels and in new ways, enabling us to grow once more in the medium term."
Pret is reliant on sales from commuters and lunchtime office workers, which are sources of revenue acutely affected by the lockdown.
The company is broadening its sales with a retail coffee initiative with Amazon and a delivery partnership with Deliveroo, Just Eat and Uber Eats. There are also click and collect trials in five shops in London.
Pret said sales across these digital channels have already grown 480% year-on-year, and now represent over 8% of total UK sales.
The company is in talks with landlords about reducing its rent bill.In May, it appointed advisory firms to help restructure the business, and in April it raised €100m (£90m) in emergency funding from its banks.
Pret, which owns 550 outlets globally employing 13,000 staff, including 8,000 in the UK, is the latest High Street food chain to announce cuts.
Last week, SSP Group, which runs Upper Crust and Ritazza, said it would cut 5,000 staff, more than half its UK workforce.
In addition, The Restaurant Group, which runs Frankie & Benny's and Wagamama, and Cafe Rouge-owner Casual Dining Group, have announced more than 4,500 job cuts between them.