What is a tax invoice and how does it differ from a regular invoice?

They want to see that you have been paying tax on your income. So a tax receipt from your country showing that

Where are you from? We do have tax invoices in my country Korea. And they're just that, tax invoices.

Why not show tax returns from your governments tax office… that would cover it.

A tax invoice is a document that has been legally recognised by the relevant government authority. It has also been issued by an authorised dealer to a purchaser. It will show the tax amount payable for the exchange of any goods or services.

Whereas an invoice is a document that is issued from a buyer to a seller that shows the amount due for the goods and services that have been exchanged.

A tax invoice is an invoice. Same same.