Our accountant company is telling us that it is time to do the yearly audit. (our first time)

We have to pay a fee of 15.000 Thb to some auditor, someone not related to the accountant company.

We have gotten a email from the company telling us that the accountant company will not sign our papers

if we do not use the company they have referred. Is this normal procedure ?

Not in the normal business world, no.

Our small company has an accountant. Every year, our accounting has to be checked and signed off by an independent auditor. We only pay 10,000 Bahts a year but the amount may depend on the size and turnover of the company.

Hope this helps.

This is normal practice over here. What anyone offers you to do anything for a cost is always higher than what it should be since they always add a bit of commission to the cost for themselves. So if you have a Thai partner, do yourself a favor and do some searching yourself. Find an auditor yourself to do it for less