sending quotation asking for payment

I am not very clear of your situation, thus, not sure if what I am about to type helps.

My 2 cents is this.

In Vietnam printed invoice is not considered invoice.

The "pink slip" which is the VAT invoice is considered an invoice.

Most companies are not able to provide the "pink slip" because many products are brought into the country illegally for the purpose of tax evasion.

If you do not require the pink slip for tax audit, you can tell them to print something and send to you.

However, I note that you say they send quotation and ask for payment. Has the deal been made?

PM me if you require me to liaise with your vendor. Sometimes, a little pressure from a 3rd party might solve. I will be glad to help.

Yep, this is Vietnam. Qoute, payment and invoice is here the order. There is no such thing like a later invoice, unless the vendor has the guts to "collect" them. Like above, make sure you get the RED BILL

In Vietnam, you can only claim expenses over 200k VND based on invoices using the registered template. It can be VAT invoice or sales invoice. Your situation is not so clear, please pm me and we can discuss further.