What is the buddy stamp duty

In the context of Singapore real estate, the term you are likely referring to is the "Buyer's Stamp Duty" (BSD), not "buddy stamp duty."

Buyer's Stamp Duty (BSD) is a tax payable by buyers when they purchase a property in Singapore. It is calculated based on the purchase price or market value of the property, whichever is higher. The BSD rates are progressive, meaning they increase as the property price increases.

As of the latest updates, the top marginal BSD rate for residential properties is 6%, and for non-residential properties, it is 5%. This duty is applicable to all types of property purchases in Singapore and is computed on the first instrument executed relating to the sale and purchase of the property.