Hi Nicolas,
Thanks, sorted.
For anyone else with this issue:
In my case - it turned out I have a letter at the end of my Vat Number as well as the country code at the beginning ( Ireland - ie ) eg
ie1234567m
This is what i tried and it did not work. The problem was simple - TRY make all letters CAPS, so:
IE1234567M
This worked.
Hope this might help others ..