UK based companies with .com domain

[jimjones44]

I just want to pick a few expert brains on here on how to solve my problem.

How would I go about finding (on mass and quickly) if a website that is a .com domain is actually a UK based company?

 

[hamd01]

 

[jimjones44]

Do a whois and see if the owner is UK based

Is there any software out there that can do this on mass? The reason I ask is that around 20,000 urls need to be checked everyday.