Northern Ireland and Eire Exam Centres Edit
Craigavon - Brownlow College - Kieran McKernan, Examinations Officer - tel 028 3834 2121, *update - now ccea only*
Newtownabbey: The Free Presbyterian School will accept home-educated children. It is a CCEA centre and is currently applying to be an Edexcel centre for IGCSEs.
Belfast - Conway Education Centre No Longer an exam center
keep an eye on their website as it states alternative will hopefully be announced in January 2020.
Dublin - The Tutorial Centre At the moment, as far as I know, you have to go to Dublin to do IGCSEs. Please update this if you know otherwise. [Feb 2020 update: they no longer offer Cambridge IGCSEs.
[Some of this information might be out-of-date. Please update if you have more recent information]