After years of campaigning by the deaf community, BSL and ISL were officially recognised as minority languages in Northern Ireland in March 2004 for about 4,500 Deaf sign language users of which 3,000 are BSL users, and 1,500 are ISL users. Although no legal status for BSL / ISL in Northern Ireland.

Useful link: 

Official Report: Minutes of Evidence Report - Northern Ireland Assembly - 13 November 2014