The BBC have seats that you can apply for,sadly all in Glasgow so ok for you folk in the North and there is no Guarantee you will get seats,but they are free,see here
http://www.bbc.co.uk/showsandtours/shows/shows/mrs_browns_boys_2012
http://www.bbc.co.uk/showsandtours/shows/shows/mrs_browns_boys_2012