I have been looking for info for a while on how WHMCS can be made compliant and given the vast resources WHMCS has I have to say this response is VERY disappointing.
A few points.
The VAT rate is to be charged based on the customers LOCATION at the time of order, not in accordance with the address they enter.
e.g. I am from the UK, my billing address may well be in the UK however if I order service from a digital merchant while I am in Germany then I pay the rate of VAT for Germany.
When I return to the UK I then need to pay VAT at the UK Rate and so on.
Merchants need to be able to display the prices pre order including VAT based on the location of the visitor, not post order confirmation.
3 Pieces of corroborating information that confirms the customers location at the time of sale (and all subsequent transactions) must be stored for no less than 10 years.
Individual VAT specific reporting must be available per EU state.
As far as I can see all the WHMCS plugin lets you do is set a VAT rate per country which only kicks in after the user presses "buy" or "order" and then enters 1 bit of information.
As such WHMCS is not compliant, this plugin does not make you compliant 1 bit and additionally as it turns out if you are in the EU (or are registered in the EU) and you decide not to sell to others outside you own state to avoid complexity you are breaking anti-discrimination laws.
I have sent a ticket to WHMCS, waiting for a reply.
Sorry but very little info in this thread is correct, doing it the way this thread is suggesting may be convenient but it is not compliant.
Also in terms of this blog post: http://blog.whmcs.com/?t=96594 it is just wrong for the reasons above and the MOSS team have had an open system and support staff in place to help people and software vendors be complaint since October, who exactly have WHMCS tried to contact?