After a few high 2 monthly bills, the last straw being €400+ (mostly eldest son’s 086 girlfriend) We got an eircom package with unlimited broadband and unlimited local/national calls. For an additional €6 two monthly fee mobiles and premiums are barred, careful though, international calls are still allowed. Typical 2 monthly bill is now is €120- €125.
As we need to be contactable and our teenagers never have any credit, we bought a house mobile for €80 (which at the time came with €80 credit). Strict house rule, it’s only to be used to contact parents or in an emergency. The free credit is long gone but would not put more than €10 monthly on the house mobile. A substantial saving overall.