Add customer variable to transactional email

[AmagArtwork]

I'm using the customer VAT id as our internal customer id field. I'd like to output that variable on the transactional emails (i.e. New Order, Invoice, etc). I can't figure out why it's not working. I have tried 

{{var order.customer_taxvat}}

and 

 {{trans "%customer_taxvat" customer_taxvat=$order.customer_taxvat}}

Am I completely off the wall that it should output something in the email?

[vishalsanwar86]

I used below code to get the customer tax/vat. It is properly working for me.
  <p>Vat Number: {{var order.getCustomerTaxvat()}}</p>
in sales order email template.

If Issue Solved, Click Kudos/Accept As solutions.

[Rakesh Jesadiya]

You can do it like below way,

{{var order.geteCustomerTaxvat()}}

another way is,

{{trans "%customer_taxvat," name=$order.getCustomerTaxvat()}}