The Treasury Department is set to ask local administrations to jointly appraise individual land plots to complete the process by next year so it can be used as a base for the land and buildings tax.
The appraisal of each specific land plot will be clearer when collecting the land and buildings tax, said director-general Naris Chaisoot.
At present, only 7 million of the 30 million land plots across the country are evaluated separately.
The land and buildings tax is among the priorities of the government as part of its effort to reduce income inequality. Others are the inheritance and gift tax. Land and buildings tax, which will replace house and land tax and local development tax, is expected to boost local administration's revenue and then reduce the government's burden subsidising them.
Finance Minister Sommai Phasee recently said the land and buildings tax would be the next one to come into force after inheritance and gift tax. The Fiscal Policy Office earlier proposed a ceiling rate of 4% for unused land and land for commercial use. For unused land, the rate would double every three years but not exceed the maximum level of 4% of the appraised value. Maximum rates will be set at 0.5% for land for agricultural use and 1% for residential use.
Mr Naris said using local administration officers to appraise the prices for specific land plots would speed up the process.
The department will be responsible for training local administration officials to appraise land, he said.
The Treasury Department's appraisal on an individual basis is based on the Lands Department's Universal Transverse Mercator (UTM) map.
The UTM map now covers 35 provinces and the Lands Department aims for the map to include all 76 provinces by next year.
The Treasury Department plans to use the map to appraise 460,000 land plots individually in Udon Thani and Khon Kaen this year and another five provinces, Prachuap Khiri Khan, Mukdahan, Nong Khai, Ubon Ratchathani and Chon Buri, next year.