The "Value Added Tax / Goods and Services Tax" add-on supports tax exemption based on the customer's VAT ID. Buyers who specify a VAT-using European country in the Country field of their address (in either the shipping or the billing address block, during checkout, or while editing the address book in their profile) will have an option to fill in an additional field - VAT number. If they have a VAT ID that allows them not to pay VAT on the purchase, they can submit it using this field.
Your online store will provide validation of the VAT number format. Then, it will submit the provided VAT number to the appropriate VAT number validation service (learn how to configure it in your store here). If the service returns information that the specified VAT number is valid, your online store will automatically remove the VAT amount for the buyer, so they will not have to pay it. However, if the service responds that the VAT number is invalid or fails to respond (this sometimes happens if the service is down or overloaded), your online store will not remove the VAT taxation for the buyer.
As mentioned above, you can specify which VAT validation service you wish to use and provide an API key that will allow your X-Cart store to connect to that service when configuring the "Value Added Tax / Goods and Services Tax" add-on.
The following validation services are supported:
VatSense: To use this option, sign up for an account with VatSense at https://vatsense.com/, and submit your VatSense API key to X-Cart as described here. All VAT validation requests will go through VatSense in this case.
Vatlayer: To use this option, sign up for an account with Vatlayer at https://vatlayer.com, and submit your Vatlayer API key to X-Cart as described here. In this case, if the buyer's address at checkout states that they are from the EU, VAT validation will be done for them through Vatlayer; if the address states that the buyer is from the UK, the validation will be done through HMRC.
NOTE: If you don't specify an API key for any of the suggested VAT validation services in your online store when configuring the "Value Added Tax / Goods and Services Tax" add-on, X-Cart will attempt to use a free service:
If the buyer's address at checkout states that they are from a country in the EU, a VAT validation request for them will be submitted using the free VIES API.
If the buyer's address at checkout states that they are from the UK, a VAT validation request for them will be submitted using the free HMRC API.