The company confirmed that it is offloading 108 crown branches, which are currently directly owned and run by the company, including 36 in London.
The process could see the sites taken over by other businesses, while others could face closure as franchises are moved to different premises.
It is understood the Post Office expects the majority of these branches to continue running at their current sites, but that some of these could face closure as franchises are moved to different premises, affecting staff.
Hundreds of people are opposed to the closure of the branch in Hampstead High Street.
Customers described the plans as “disgraceful” and hoped the Post Office would not close the “thriving” branch.
They told the Ham & High they use it to buy stamps, send and return packages, get forms, buy foreign currency, and pay bills.
Golders Green Post Office in Finchley Road could also be taken over by a franchise.
Barnet Labour councillors last year launched a petition to save the post office saying it was a “lynchpin” of the high street.
Cllr Nigel Young, who represents Childs Hill ward, said: “Closing it would be a blow to our local economy and community. Let’s fight together to keep it open.”
Hundreds of people also signed a petition to save Cricklewood Broadway Post Office, described as being “at the heart of the community”.
The branch in Kilburn High Road, on the Camden and Brent border, is also on the list.
Others listed were in Headstone Drive, Harrow; Upper Street, Islington; and Stamford Hill, Hackney.
The Post Office said the plan, which is subject to Government funding, will help it to increase postmaster remuneration by an extra £250 million a year by 2030.
Post Office chairman Nigel Railton said: “Moving to a fully franchised network is one part of enabling the Post Office to deliver a New Deal for Postmasters, helping to create a long-term, sustainable future for the Post Office.
“By franchising these branches, we are protecting access to our services for communities right across the UK and realising £40 million worth of savings that will enable us to uplift postmasters’ remuneration by up to 10%.”
