A single plot carries at least two prices. The Land Department's assessed value sets the taxes; the market price is what it changes hands for. Knowing which is which keeps the sums right.
The same plot carries at least two prices, they can be far apart, and each does a different job.
The Treasury Department publishes assessed values on a cycle, by area and by road. That figure is used to calculate:
Assessed values are usually below market, sometimes well below, which works in the taxpayer's favour: it lowers the base the charges are calculated on.
What a buyer and seller actually agree. It depends on demand, supply, location, the condition of the plot, and how much hurry either side is in.
Nobody publishes it. It has to be estimated by comparison with what has genuinely sold nearby.
Assessed values are revised only every few years, so they lag the market wherever prices are moving.
They are also set by zone along a road rather than plot by plot. A riverside plot and an inland plot on the same lane can carry the same assessed value while their market prices differ several times over.
That is why the gap between the two numbers tends to be wider on waterfront land than on ordinary land.
Calculating fees and taxes — the assessed value. Ask at the local Land Office; it takes little time.
Deciding whether an asking price is reasonable — the market price, compared against similar properties in the same area.
Applying for a mortgage — the bank uses its own valuation, a third figure, usually between the other two. That is the one that sets how much will actually be lent.
Declaring a sale price below the true figure to reduce tax is done, and it carries risk.
If a dispute arises later, the price in the contract is the price the court works from, and a buyer who paid more than was declared may not be able to prove the difference.
Under-declaring also costs on the way out: the calculated gain on a future sale is larger, so the tax on that sale is higher.
Look at what is currently advertised in the same area, then adjust for differences in size, frontage, access and condition.
Remember that an asking price is not a sale price. The gap between the two in the Thai market is usually real negotiating room, and it depends on how much the seller needs to sell.
Waterfront land carries building restrictions ordinary land does not: setbacks from the water, Marine Department permits, and zoning. What to establish before paying for a design.
Two riverside plots of identical area can be worth very different amounts, because of how much of each touches the water. Why that is, and how to compare them properly.
The annual tax is set by how the land is used, not by value alone. Land left vacant is taxed at the highest rate, and the rate climbs every three years.
