About 100,000 homes (from the total 650,000 in the province) will get Freeviewservices for the first time.
On October 10 2012, analogue BBC2 will be turned off as a final reminder to viewers who have yet to switch.
Denis Wolinski, Digital UK's national manager for Northern Ireland, said: "Today is an exciting day for television in Northern Ireland. This announcement paves the way for the end of analogue TV and the dawn of a fully digital age in which everyone can enjoy more channels, more choice and better pictures."
He said Digital UK will ensure that people know what to do and that advice and practical support is available to those who need it.
A campaign will begin this spring including roadshows, advertising and an information leaflet sent to every home.
A help scheme will be offered to older and disabled people providing support including equipment and installation.