Published Friday, 09 March 2012
The move affects the Post Office network across the UK. (© Getty)
The scheme, which will be rolled out over the next three years, will see a total of around 6,000 branches revamped and modernised - and opening hours lengthened.
Northern Ireland has about 480 Post Offices.
Regional Manager for NI, Sheila McCann, said the investment will provide a "more modern and convenient retail experience" for customers.
"This is a once-in-a-generation opportunity for the Post Office - a chance to revitalise the network and allow it to meet the current and future needs of our customers and communities nationwide," she said.
"This major investment will help Post Office Ltd address changing customer needs by revitalising the network, with extended opening hours and a better experience for our customers."
There are 11,800 branches of the Post Office across the United Kingdom.
Officials said all branches across the network will benefit either directly or indirectly from the investment scheme.
They added that the 5,500 branches which will not become local or main branches will retain their current operating model and will be supported by subsidy payments.