[lxgr]

There's no charge for incoming calls from abroad while at home: All EU countries use "caller pays" billing (unlike the US, which historically has used shared cost for mobile phones).

That's why there are prepaid SIMs without a monthly fee and unlimited incoming calls: The caller's operator pays the called operator a termination charge by the minute.

There is an incoming call charge while roaming, the rationale being that the caller doesn't know where you are and needs predictability in pricing (so the called party pays for the leg from their home country to where they are), but the EU has capped that to zero within the EEA.