Hi,
AVS support kind be done in three ways:
- the payment gateway supports it (with a different name probaby) and in that case, if activated for your merchant account, when it sends the payment notification to your website, it will include AVS security result check so that you can potentially block or not the confirmation of the order or sometimes even the payment. In that case, it requires modification to the payment plugin.
- Sometimes, when you activate it in your merchant account, the check is done during the payment process and thus there is nothing to do in the payment plugin as the transaction is only accepted if it pass the check (that's the best way I think).
- You can also implement a custom plugin to integrate with a third party AVS check web service so that even if your payment gateway doesn't support it you can do it.
So the first thing to do is to check with your payment gateway merchant support what they offer.
If you're in Europe, then use a payment gateway where you can activate the 3d secure. That will prevent fraud regardless of the shipping address. That's the best method.
If you're not in Europe, then AVS is what you want but I'm not familiar with that much.
I know that Authorize.net has options in that respect if you're in the USA and no modification is needed in the plugin for that :
account.authorize.net/help/Account/Setti...ion_System_(AVS).htm