Originally from ticket #206.

Scottish Charity numbers are registered with the Scottish Charity Commission: https://www.oscr.org.uk/

Northern Ireland Charities are included in the Deemed List: http://www.charitycommissionni.org.uk/Our_regulatory_activity/List_of_deemed_charities.aspx

I'm currently working with a dataset from Big Lottery Fund that includes Scottish and Northern Ireland charities.

Prefixes such as

GB-SC for Scottish Charity Register

and GB-NICH - for Northern Ireland Charities Commission Deemed List

would be useful.