You can just trust IP geo databases to be accurate down to the country* - and that's only most of them time and not even considering VPNs exist.
Sure, if something looks fishy you could then go through the appropriate legal channels to get a more exact location from the ISP, but false positives are going to happen so often, eventually everyone involved might get a bit cranky.
* Only the likes of Google have the scale and requisite information to keep more accurate and up-to-date databases, and even those are fallible.
> You can just trust IP geo databases to be accurate down to the country*
You can't trust even that. There's an ISP which shares the IP pool between its child companies (? or some similar arrangement) in Crimea and Poland. We found out when Polish subscribers got affected by sanctions on business with Crimea.
My home IPs get placed into another country by geolocation all the time (it's probably more wrong than right). My VPN IPs (for which I always use either Finland or the Netherlands) have been geolocated to: three states in the US, Dubai, and several other EU countries.
Sure, if something looks fishy you could then go through the appropriate legal channels to get a more exact location from the ISP, but false positives are going to happen so often, eventually everyone involved might get a bit cranky.
* Only the likes of Google have the scale and requisite information to keep more accurate and up-to-date databases, and even those are fallible.