IP2location:
https://www.ip2location.com/demo/
IPINFO:
https://ipinfo.io/
DBIP:
https://db-ip.com/
MAXMIND:
https://www.maxmind.com/en/home
Until your GEO's are updated on all 4 websites, you should NOT use them unless you want to get your ranges blocked. You would occasionally go to ALL FOUR, and put in an IP from your subnet. For example your subnet is 56.2.123.0/22 as the straight allocation. You would check https://www.ip2location.com/demo/56.2.123.0 (without the CIDR).
In this particular case, a /22 = 4 x /24s. So if you want, you would check all four of the /24's changing the last number as follows:
https://www.ip2location.com/demo/56.2.123.1
https://www.ip2location.com/demo/56.2.123.2
https://www.ip2location.com/demo/56.2.123.3
Each website has their different "demo" or whatever it is called.
Anyway, to your question, once ALL FOUR show U.S. GEO, then you're off to the races and it is safe to start using your ranges.
