If i issue a Tax Invoice without VAT to a company outside thailand? i have the proof of sending the goods out of thailand (EMS postal receipt). Do i need to have an "export permit"?

International shipments by EMS are subject to VAT!

We have learnt this the hard (costly) way when we were audited by the revenue department a few years ago.

In order to have any shipment exempt from VAT you have to provide:

1) Proof that the funds matching the invoice came from abroad

AND

2) The customs export declaration form ใบขนสินค้าขาออก (กศก. 101/1)

Since our audit we have taken all EMS shipments off the books and send them as private deals.

opalhort

Thanks Opalhort. Looks like that is the way to go then.

Opalhort is correct. the reason being, the EMS slip does not state what kind of products you have exported. Only a customs export declaration would do that.