Originally Posted by mrgs12:
“Is there an opt out clause for indoor coverage obligation in areas where the majority of buildings are thick walled? My area upgraded to 3G/4G but it still noted on coverage checker Ok outdoors. Variable indoors not suitable for tablets/smartphone internet use. 2G is no better.”

I'm sure the "indoor coverage" marker is determined by the field strength from a cell site from which it would be expected that indoor reception is possible most of the time. It would be impossible for it to cover all buildings, especially those whose construction makes UHF frequency penetration difficult/impossible.