Yes, the county-dependent fax notification stuff is a nightmare. I think it applies to Police / Special Branch notifications (applicable only to flights between GB and the CTA (Ireland N or S, IOM, Channel Islands). Half the published fax numbers don't work, and if you send the fax to a neighbouring force's fax #, you get a phone call from a stroppy jobsworth Plod who is not at all interested in knowing why the right fax # did not work (e.g. no paper in the machine).
It is about time they all joined up and set up a single point for filing the GAR.
EuroFPL is an excellent product already (especially with the ability to delay a flight plan by sending an SMS message) and this will be really ace.