Option to verify European tax_id's on registration / first orders only
As a European company, we need to verify European tax Id's from companies based in other European countries. So far so good. You can do this once (registration / first order), or for every order (this is how WHMCS is doing it right now).
The problem with verifying every single order is, that e.g. German VIES servers are unavailable quite often. What happens then is, that a customer who has successfully placed 20 tax-free orders with us previously, suddenly gets charged 19% VAT on his 21st order, because his tax id couldn't be verified just because German VIES tax id servers are YET AGAIN not working properly.
Our customers are getting really mad about this. - And they have all the right to get upset.
This is happening all the time with us, because we are selling mainly to Germany. We've had 20 customers affected by this just in the past 45 days alone !!! In fact, we are losing customers, because of this !
Solution: offer an option in WHMCS, so we can chose that VAT validation only occurs for new customers, not for every order. We have used this in the third party VAT WHMCS add-on previously, and this has created much less problems for us. What can happen then is, that a customer's VAT has expired, and they are still using it. This is very uncommon though, and creates much less problems, and: it doesn't upset our customers !!