It launched a scheme for 500 UK teenagers amid looming staff shortages, with the Guardian reporting the young people would only get free food.
But following online criticism, the sandwich chain said it would pay participants and give them free food.
The firm said it saw "how passionately people feel about the initiative".
One in 50 Pret applicants is British
The company launched its Big Experience Week after it said it would struggle to staff its outlets following Brexit because just one in 50 job applicants is British.
Its director of human resources, Andrea Wareham, said UK job seekers did not see it as a desirable place to work.
The Big Experience Week would give participants exposure to aspects of its business, including food production, customer service, "social responsibility" - described as care for the homeless - and financial control, Pret said.
However, following criticism on social media that the placements would be unpaid, the company tweeted a statement saying it would now be paying participants.
Pret CEO Clive Schee said: "Pret's work experience week is not about making sandwiches for free.
"We set it up so that 16-18-year-olds can shadow our teams and get a flavour of what working at Pret is like.
"We've seen how passionately people feel about the initiative, and in response I would like to confirm that we will pay all participants."
A spokeswoman for the company added that the teenagers were "not there to work themselves" and would instead be shadowing team members.

Lagmar Barking, a joint venture between MAR Properties and the Lagan Developments (Holdings), owned the Vicarage Field shopping centre in Barking.
It has been bought by Benson Elliot, a UK-based private equity property fund manager.
The last accounts for Lagmar Barking showed it owed its lenders £70m.
The loan secured on the centre was bought by the US investment fund Cerberus as part of its purchase of the National Asset Management Agency's (Nama) Northern Ireland loan book in 2014.
Peter Cornforth, director of retail at Benson Elliot, said the deal was "an exciting purchase for Benson Elliot".
He added that it provided the firm with "a fantastic opportunity to contribute to the regeneration of a key east London metropolitan centre".
Cerberus is continuing to rapidly work through the former Nama portfolio with a combination of asset sales, refinancings and enforcements.

Ashley Brace, from Ebbw Vale, Blaenau Gwent, could not compete at the Commonwealth Games because of her kickboxing past.
She said she was unhappy with the support from the Welsh Amateur Boxing Association (WABA).
Chairman David Francis said the organisation did all it could to help.
The Association of International Boxing Associations (AIBA) said Brace was ineligible to compete for Team Wales because she had competed in professional kickboxing in the past, which she denied.
Organisers of the kickboxing tournaments she competed in have also since confirmed she did so on an amateur basis.
A further rule states any boxer returning from another individual contact sport should apply to an international committee to become eligible to box again.
Brace said she was never told about the paperwork, which had to be submitted by WABA, and felt the association let her down.
She now trains at Bristol Boxing Gym and has her first professional fight in Newport on 30 October.
She added: "I would never go back to Team Wales after this, because if you don't have confidence in the people who are supposed to be fighting your corner, at the end of day, what's the point?"
Mr Francis said the whole incident was "regrettable".
Pret A Manger has said it will pay teenagers on a week's work experience its starting hourly rate after reports it planned to "pay them in sandwiches".
[NEXT_CONCEPT]
A shopping centre in east London that had been owned by two Northern Ireland property groups has been sold for £35m.
[NEXT_CONCEPT]
A former Welsh amateur boxing champion said she is turning professional as she does not have confidence in the governing body.