# Comparison of vendor tax and self-assessed tax

Source: https://developer.avalara.com/vat-erp/certification-requirements/comparison-vendor-and-self-assessed-tax/

**Element type:** Suggested for Input VAT

**Endpoints/models used:** N/A

AvaTax users who purchase goods from a supplier will receive an invoice with VAT calculated. ERP systems must be able to compare what AvaTax calculates as the tax versus what was actually received on the invoice.  

This requirement is handled through your backend and not directly via an AvaTax API call.