It is often not so obvious and agreeable between buyer and seller who is supposed to shoulder which type of expenses that typically incur during the acquisition of real estate and its registration with the land department. 
Buyer, Seller and Agent (if applicable) should clarify this at an early stage instead of making silent assumptions that later on have to be corrected to the disappointment of the one or the other or all sides.
 

PURCHASE/SALE OF LAND

The following fees apply: 

Transfer fee* = 2% on the official land appraisal price from the land department;
(The official appraisal is the minimum base of calculation for the transfer fee. If the declared actual selling price is higher, the 2% will be levied on that higher value.)
3.3% business tax on the actual selling price; 
0.5% stamp fee. 

Note regarding the business tax:
A legal entity is always required to pay 3.3%, independent from any holding period. 
An individual owner/seller will be assessed at the land department and the holding period goes into the formula (where less than 10 years of ownership will draw a higher business tax). 

PURCHASE/SALE OF A CONDOMINIUM

Currently,* the transfer fee = 0.01% of the land department appraisal;
3.3% business tax (if less than 5 years owned and not occupied by owner). 
Not an initial fee but possibly later quite relevant: A condominium maintenance fee can range for instance from 2,000.- to 8,000.- Baht/month. This could be a relevant factor especially in the case where the unit is bought as an investment and rental property.

*The transfer fee has been temporarily reduced. We hear that increases are expected to be implemented "soon" (probably early in 2000).

Corporate income tax is 30% on net income. In some cases companies had been formed just to create a legal entity ownership over a particular real estate. If the buyer agrees to purchase the company together with that particular asset the direct ownership of the real estate does not change and there will be no taxable income. The object of sale will be the company shares and only the personal income situation of the seller will be taxable.

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Disclaimer: Although the information in this article has been obtained from sources believed to be reliable, we do not guarantee its accuracy and such information may be incomplete or condensed and is subject to changes from time to time. (Status: December 1999)