The 08 numbering range was previously used for calls to Northern Ireland, but following the UK's renumbering of Northern Ireland in 2000, this changed, so to call a number in Belfast from the Republic:
Northern Ireland
Web Site
Northern Ireland - Ireland - Europe Phones
Northern Ireland - Ireland - Europe Phones
Northern Ireland Europe
Northern Ireland 2024 Banbridge: Man in critical condition after car park shooting BBC.com
Man in 40s arrested following shooting in Banbridge car park | PSNI PSNI
Banbridge shooting: Victim 'critical but stable' after being shot by masked man Belfast Telegraph
Sinn Féin's track record on housing in Northern Ireland is nothing to write home about Belfast Telegraph