Depending on your country's billing address you have the possibility to enter your tax ID to reflect on your invoices. To add or update your tax ID in your account, go to your Billing tab and select the pencil icon in the Billing details section.
Scroll down to the Address section and fill in the tax number field that appears there.
If you have a European billing address, you will have the possibility to add your VAT number.
If you have an Australian billing address, you will have the possibility to add your ABN.
In some other countries such as Norway, Turkey, Taiwan, South Korea, Belarus, Singapore, and New Zealand, you will also have the possibility to add your tax ID number to your account.