I noticed a missed call from a Polish number starting with 70X and decided not to return it. Are these numbers associated with premium services? I’d like to identify the number without accidentally generating charges.
I’d definitely avoid calling an unfamiliar 70X number until you know what kind of service it represents. Some Polish numbers with special prefixes can have different charging arrangements, so checking first is sensible. You could search the number on https://scannero.com/who-called-me/poland/ and see whether there is information about it or reports from other users. If the number appears connected with a paid service, I’d avoid returning the call unless you specifically know why you were contacted.