Check VAT number against VIES: http://ec.europa.eu/taxation_customs/vies/

The Program is written in Go, I tested it on Linux and Windows

go install github.com/jramb/vatcheck

or you can clone or download this repository and do go install or go build.

./vatcheck SE556950473001
Result: SE556950473001 = true
Name:  Navigate Approval Solutions AB
       c/o KISTA SCIENCE TOWER 
FÄRÖGATAN 33 
164 51 KISTA
Date:  2016-02-20+01:00

on Windows use vatcheck.exe

This program is not endorsed by the VIES service. Please see the VIES disclaimer and FAQ on the VIES homepage http://ec.europa.eu/taxation_customs/vies/viesdisc.do before using it and comply with the terms of usage outlined there.

This program is put here as-is. If it stops working: not really my problem.

And always pay your taxes!