Homeless people will be offered an address by An Post to help them access services or apply for jobs.
An Post says Address Point will enable people with no fixed abode to open a bank account, apply for school places for children, and deal with medical appointments.
A number of homeless services are working with An Post.
The initiative will be rolled out in the next few weeks.
It comes after the postal company officially launched its major rebrand yesterday.
Despite financial difficulties several years ago - including a loss of €12 million in 2016 - the company has returned to profitability.
Early financial results showed An Post managed an operating profit of €40 million - up from €8 million in 2017.
The company says a "global decline" in letters was offset by a 40% volume growth in parcels.
CEO David McRedmond said their shift into e-commerce and financial services helped them deliver "great results".
Last year, An Post said more than 150 post offices are set to close as the serving postmaster has opted to retire.