Bangkok property tax bills could rise 8-12% starting 2027

The Bangkok Metropolitan Assembly passed a preliminary reading of the Property Assessment Modernisation Bill on July 9, moving the legislation closer to final approval. The bill requires the Bangkok Property Valuation Office to update assessment methods and recalibrate property values across the city using data collected over the past five years. For Bangkok residents, the change means property tax bills will likely rise when the new assessment system takes effect in October 2026.

The revaluation affects an estimated 412,000 residential properties and 78,000 commercial properties within Bangkok's administrative boundaries. Current property assessments have not been comprehensively updated since 2015, and city officials argue that eleven years of property market changes warrant a refresh. Real estate values in central and mid-town Bangkok have increased substantially, particularly in zones near the BTS Skytrain and MRT lines. The Property Valuation Office says the new methodology will use recent market sales data, rental comparables, and location-specific factors to determine fair values.

What Bangkok Homeowners and Businesses Should Expect

A Bangkok resident with a 60-square-metre mid-rise condominium in Sukhumvit assessed at 2.4 million baht under current rules could see the reassessed value reach approximately 2.7 to 2.8 million baht. Property tax in Bangkok is calculated at 0.02 percent of assessed value for owner-occupied residential properties and 0.04 percent for investment properties and commercial spaces. That means an annual tax bill on the Sukhumvit unit would increase from roughly 480 baht to between 540 and 560 baht per year. For commercial shophouse owners in Ratchathewi or Huai Kwang districts, where land values have risen faster, increases could reach 15 to 18 percent depending on location and recent comparable sales.

Policy analysts note that the revaluation disproportionately affects properties in high-demand areas. Residential developments near Phraya Nakhon Park, along the Chao Phraya riverside zones, and in the eastern expansion zones near Suvarnabhumi Airport are projected to see reassessments of 20 percent or higher. The Bangkok Chamber of Commerce has flagged concerns about retail storefronts along Yaowarat and Sampeng Lane, where small business owners operate on thin margins. The Metropolitan Assembly included a six-month payment plan option in the final bill language to ease the transition for property owners.

Timeline and Implementation Process

The Bangkok Property Valuation Office is scheduled to begin issuing new assessment notices in September 2026, with property owners given 30 days to request a review before the October 1 implementation date. Owners can appeal assessments to the Bangkok Appraisal Tribunal, an independent body that reviewed 4,287 property appeals in 2025 and overturned or reduced assessments in approximately 31 percent of cases.

The bill received a 52-to-18 vote in the Assembly's preliminary reading. Final approval is expected by late August. Budget officials say the city government projects an additional 2.1 billion baht in annual property tax revenue once the new system is fully operational, representing approximately 18 percent growth over current collections. That revenue is earmarked for flood mitigation infrastructure in low-lying areas of Thonburi and Lat Krabang, water treatment facility upgrades, and public transport connections to outer districts.

Bangkok residents can request a full copy of the revised Property Assessment Modernisation Bill from their district office or view the complete document on the Bangkok Metropolitan Council website. The Property Valuation Office is also opening walk-in consultation hours at its Ratchadamnoen Avenue office from July 15 through August 31 to answer questions from property owners.