New Tax Measures to Promote Solar Rooftop Installations and Energy-Efficient Equipment

On 25 November 2025, the Thai Cabinet approved (in principle) a draft Royal Decree under the Revenue Code that introduces two tax incentives to further Thailand’s national energy policy to expand household solar power generation, enhance energy efficiency (particularly in industrial operations) and support Thailand's long-term goals for carbon neutrality and net zero emissions. The new tax incentives are:
(1) a tax measure to support solar rooftop installations on residential properties, and
(2) a tax measure to encourage investment in high-efficiency machinery, equipment, and energy-saving materials.

1. Tax Incentive for Residential Solar Rooftop Installations
Individual taxpayers will be granted a personal income tax deduction for expenses relating to the purchase and installation of solar rooftop systems connected to the Metropolitan Electricity Authority or Provincial Electricity Authority grid.

Conditions:

• Deduction allowed for the actual amount paid, capped at THB 200,000.
• Expenses must be paid to a VAT-registered supplier that issues an e-Tax Invoice as evidence.
• Each individual may use the deduction once, for a single system.
• The deduction must be claimed for the tax year in which the system is successfully connected to the electricity grid.
• The same expenses cannot be used for any other tax exemption measures.
• The Royal Decree will remain in effect until 31 December 2028.

2. Tax Incentive for High-Efficiency Machinery and Energy-Saving Materials
Individual taxpayers will be granted a personal income tax deduction for expenses relating to investments in high-efficiency machinery and energy-saving materials certified with a 5-star energy efficiency label by the Department of Alternative Energy Development and Efficiency. 

Conditions:

• Limited to individual taxpayers earning income under Sections 40(5)–(8), and companies or juristic partnerships
• The deduction is available for 1.5 times the actual investment cost.
• Eligible expenses must be paid to a VAT-registered supplier that issues an e-Tax Invoice as evidence.
• The Royal Decree will remain in effect until 31 December 2028.

Please continue to monitor the conditions and criteria for, and the detailed requirements to claim, the tax exemption. We will update you after the relevant law is promulgated and comes into effect.

This article is intended to provide only a regulatory overview, and is not intended to be comprehensive or to constitute legal advice. If you have any questions on this or on other areas of tax law, please do not hesitate to contact our Tax Team at SCL Nishimura & Asahi Limited.

Budhima Kerdsiri
Counsel

Hatairat Sukprasert
Associate

Authors