I need to know how to exempt a customer in Avatax from WooCommerce.
TaxNow for WooCommerce
Customers who use ECMS in the admin console can make a certificate for that customer.
Once the certificate is made you then need to be sure that the customer code passed from the ERP is verbatim the same customer code the cert has for your exempt customer.
If this doesn't fix your issue, we recommend upgrading to the latest version of WooCommerce.