It is important to have your Tax/VAT number on the Invoices. You can add Tax/VAT number during the checkout. It will remain same for all the purchases afterwards until you change it.

If you forgot to add your Tax/VAT number during checkout, you can add through WordPress admin dashboard.

1. Navigate to the plugin account menu.
2. Click on ‘ Billing & Invoices ‘
3. On billing section, click Tax/VAT ID field.
4. Enter your Tax/VAT ID.
5. Click Update.

After entering Tax/VAT ID, you will see the same number in all purchases inovice.