My original dumb ‘phone costs me £0/ month but I am charged for its use, whether calls or texts. Every now and then I have to buy ~£20 worth of credit. I only use it as a back up and for emergencies.
There are lots of fancy jargon words floating around but I believe that “traditional pay as you go” is the correct description of this service.
The question is whether iD Mobile offers such a service?