Home Solar Tax Deduction in Thailand Up to 200,000 THB (2026)
Can you really deduct your rooftop-solar installation cost from personal income tax — how much, who qualifies, and what documents do you need? This page summarises the deduction under Royal Decree No. 805 (B.E. 2569): a cap of 200,000 THB, an on-grid system of ≤10 kWp, who is eligible, the required e-Tax Invoice, and how to claim when you file — with a table showing how much tax you actually save at your own bracket.
Yes — a home rooftop solar system can cut your personal income tax by up to 200,000 THB under Royal Decree No. 805 (B.E. 2569). The core conditions: an on-grid rooftop system of ≤10 kWp, on your own residential home (Type-1 electricity user), filed by an individual taxpayer, with the same name on the tax invoice, the meter, the grid-connection application and the tax return. You may claim one system, once, per person, in the tax year the system is successfully connected to the grid, and you must hold a full electronic tax invoice (e-Tax Invoice). The right runs through tax year 2028 — the tax you actually save = 200,000 × your top marginal rate (see the table below). Confirm details with the Revenue Department hotline 1161.
How Much Tax Can Home Solar Deduct in 2026?
**Cap and core conditions at a glance** (per Decree 805) — the figure is a ceiling; if your install costs less than 200,000 THB you claim only what you actually paid:
| Maximum deduction | 200,000 THB (VAT incl.) |
|---|---|
| System type | On-grid rooftop solar |
| System size | ≤ 10 kWp |
| Electricity user type | Type 1 (residential) |
| Eligible person | Individual (Sec. 40(1)–(8)) |
| Claim limit | 1 system / once per person |
| Valid through | Through tax year 2028 |
Who Can Claim the Rooftop-Solar Deduction?
The deduction is aimed only at individuals installing solar on their own home. Who qualifies, per the announcement:
An individual with income under Section 40(1)–(8) who files personal income tax (juristic persons cannot use this — see the business route below).
Installed on the taxpayer's own residential home (Type-1 electricity user) — rented property or a non-residence of the filer does not qualify.
An on-grid rooftop system of at most 10 kWp, and a new installation (not a pre-existing system claimed retroactively).
The name must match at all four points: the buyer on the e-Tax Invoice = the electricity-meter owner = the grid-connection applicant = the tax filer.
One system, one claim, per person, filed in the tax year the system is successfully connected (interconnected) to the grid.
Claimable through tax year 2028 (Decree 805's window). It is separate from the excess-sell-back program and from business depreciation/BOI, so they do not cancel each other — but the same expense cannot be used twice.
Note: the No.5 energy label is NOT a condition of this 200,000 THB solar deduction (the label rule belongs to a separate energy-efficient-equipment measure). Confirm edge cases with the Revenue Department hotline 1161.
How to Claim & What Documents You Need
The key to claiming is “complete documents, matching names.” Keep the evidence from installation through successful grid connection, then enter it when you file personal income tax (PND.90/91):
Buy from a VAT-registered seller & get a full e-Tax Invoice
The invoice must be a full electronic tax invoice (e-Tax Invoice) issued in the filer's name, itemising equipment and installation-service charges separately. You can verify the issuer in the Revenue Department's e-Tax Invoice system (etax.rd.go.th).
Install an on-grid ≤10 kWp system & file grid interconnection
The right is tied to the “tax year the grid connection completes,” so finish the parallel-connection filing with MEA/PEA (see the home grid-parallel application steps) and keep the approval/connection record as evidence for the year you claim.
Assemble documents with matching names on every one
Core evidence set: (1) the full e-Tax Invoice, (2) proof of payment, (3) proof of Type-1 residential meter/home ownership, (4) the grid-interconnection record — all in the same filer's name.
Enter the deduction when filing PND.90/91
Enter the installation amount (up to 200,000 THB) in the deduction/exemption field the Revenue Department designates, in the tax year the connection completed. You can file online via the Revenue Department's e-Filing and should retain the documents in case of audit.
How Many Baht Does 200,000 Actually Save?
Because it subtracts from income rather than refunding cash, your real saving depends on your top tax bracket. This table illustrates the ceiling of 200,000 THB (200,000 × rate) — your actual figure depends on your net income and other deductions:
| Top marginal rate | Max tax saved (THB) |
|---|---|
| 5% | 10,000 |
| 10% | 20,000 |
| 15% | 30,000 |
| 20% | 40,000 |
| 25% | 50,000 |
| 30% | 60,000 |
| 35% | 70,000 |
Deduction vs Sell-Back vs Business Depreciation
About the Author
Compiled by the CapSolar team under Frank Lee (Founder). CapSolar is a commercial & industrial solar EPC/PPA provider in Thailand that condenses energy policy and official paperwork from primary sources so households and businesses can decide with confidence. This page is general information, not individual tax advice — confirm with the Revenue Department before filing.
FAQ
Your Business Gets Bigger Tax Breaks Than a Home
This 200,000 THB deduction is for homes — but if you own a business or factory, depreciation/expensing and BOI privileges are far larger. CapSolar gives a free assessment from your actual bill: which of EPC or PPA and which tax route fits your site best.