The announcement was made just 24 hours after furious union leaders threatened strike ballots after senior management and Westminster politicians said the proposed sell-off would go ahead.
Divisions deepened when Royal Mail said around 2900 employees in Glasgow will receive free shares when the business is floated on the London Stock Exchange in the coming weeks.
In total, roughly 150,000 postal workers will be eligible in what will be the largest free allocation of shares of any major UK privatisation.
Every eligible full-time staff member will receive the same number of shares. A smaller amount will also be given to part-timers.
Free shares can be sold after three years and workers are also getting the chance to make more money. They will be given priority over the general public when applying to buy additional shares.
They will be charged the same as other buyers up to a maximum investment of £10,000.
Royal Mail chief executive Moya Greene said: "Our people are the heart of our business at Royal Mail. By owning 10% of the company, together we will have a meaningful stake in the business."
But a spokeswoman for the Communication Workers Union said: "Postal workers are angry at the government's attempts to privatise their jobs and service and remain determined to fight this.
"No-one's going to say no to free money, but the shares issue is a sideshow. We're more interested in securing guaranteed higher pay in the pockets of postal workers and protecting their jobs, terms and conditions for the long term."