The Non-Subscribing Presbyterian Church (the Unitarian Church) has its origins back in 1725, when a number of congregations refused to subscribe to the Westminster Confession of Faith and formed themselves into a separate Presbytery of Antrim. Some of the early Non-Subscribing Presbyterian Church records, created before the split, are in fact Presbyterian Church records.

Some Non-Subscribing Presbyterian Church records have been deposited with the Public Record Office of Northern Ireland and they have copied some others (MIC/IB and CR/4).