BOI Solar Incentives Thailand 2026 8-Year Tax Holiday

1. What is BOI and why solar qualifies

The Thailand Board of Investment (BOI) grants incentives to attract investment. For factory solar, three frameworks apply: (1) **Category 7.1 Renewable Energy** — renewable electricity generation gets 8-year CIT holiday, 0% import duty, work-permit quota; (2) **Section 30 Energy-Efficiency** — factories holding existing BOI certificates that invest in solar to reduce grid usage get +3 years CIT; (3) **EEC Section 3** — factories in Rayong/Chonburi/Chachoengsao receive +50% CIT on the eligible portion. Details follow below.

2. 8-year corporate tax exemption — real savings breakdown

Thai corporate income tax is 20% flat. BOI **exempts** CIT (not reduces) on net profit from the promoted project. Cumulative exemption cannot exceed 100% of the investment amount (except for priority S-curve technologies). Example: a 2 MW system with THB 55M CAPEX generating ~THB 12M/yr net profit from electricity savings → normal tax ~2.4M/yr → under BOI = 2.4M × 8 = THB 19.2M saved (cap THB 55M applies, so 8 years run out first). At this scale payback drops from ~4.8 yr → 3.8 yr.

3. Eligibility matrix

Six key criteria you must meet. 80%+ of CapSolar customers pass all criteria. Most rejections are due to incomplete documents, not failure to qualify.

4. 5-step BOI application flow

Total timeline from document prep to board approval: 90-150 days. CapSolar's BOI-filing team handles all steps end-to-end.

1. 1

   Step 1 · Pre-submission document preparation

   Duration P14D

   Gather corporate documents (DBD certificate, DIW Type Ror Ngor 4 factory license, 2 years financials), investment plan, energy study proving consumption + solar offset %, and EPC quote for CAPEX baseline. CapSolar document prep service helps at this stage — incomplete docs are the #1 reason BOI board rejects applications.

2. 2

   Step 2 · BOI online portal registration + submission

   Duration P7D

   Go to https://www.boi.go.th — create company user account · complete Form F PA PP 01 (Investment Promotion Application) · upload all documents · specify BOI category 7.1 Renewable Energy (for solar EPC) or Section 30/31 (energy-efficiency upgrade) · filing fee THB 50,000-200,000 depending on CAPEX size.

3. 3

   Step 3 · BOI officer review (technical pre-check)

   Duration P45D

   BOI staff review documents, request clarifications via portal (common ask: energy audit sign-off by licensed Professional Engineer, PE) · site visit may be scheduled · this stage takes 30-60 days · incomplete submissions are rejected and must be re-filed.

4. 4

   Step 4 · Board of Investment review + decision

   Duration P45D

   After technical pre-check passes, application goes to BOI Committee (meets biweekly) · reviews eligibility, benefits level, conditions · issues promotion certificate (BOI Certificate) with ID, date of grant, benefits list · takes 30-60 days after pre-check.

5. 5

   Step 5 · Acceptance + ongoing compliance

   Duration P14D

   Company must accept promotion certificate within 6 months + submit annual report to BOI (production volume, tax claimed, energy generated) · use CapSolar calculator tools for monitoring + annual reporting · total timeline from application to operating: 4-6 months.

5. EEC zone bonus — +50% CIT stacking

The Eastern Economic Corridor (EEC) covers **Rayong, Chonburi, and Chachoengsao**. Under EEC Act B.E. 2561 Section 3, BOI-promoted businesses located in EEC zones receive **+50% of the BOI CIT exemption** (not +50% tax rate — +50% longer exemption). Example: 8 years BOI + 4 years EEC = 12 years total. Conditions: must be in an EEC promotion zone (not every location in the province), and investing in S-curve industries (EV, smart electronics, robotics, etc.). See Rayong EEC guide and Amata Chonburi for more.

6. Required supporting documents

**Corporate**: DBD certificate (≤6 months old), DIW Ror Ngor 4 factory license, corporate authorization, shareholder structure. **Financial**: 2 years auditor-signed statements, Tax ID, prior BOI certificates if any. **Project**: 5-year investment plan, **energy audit report** signed by a Thai Professional Engineer (PE), 25-year financial model (IRR, NPV, payback), module + inverter spec sheets, solar yield study (World Bank Global Solar Atlas), 1 MW BOM reference, EPC quote, roof loading certificate (rooftop), draft PEA/MEA interconnection agreement. **CapSolar helps**: we prepare everything except corporate/financial docs — contact our team for templates.

7. Non-tax benefits

Beyond CIT exemption and 0% import duty, BOI also grants: (a) **Work permit quota** — hire foreign specialists (engineering, PM) free of the 4:1 Thai-to-foreign and capital conditions; (b) **Land ownership** — 100% foreign-owned companies can hold land for factory/energy projects (normally blocked under FBA); (c) **Long-term visas** (LTV/SMART) for key personnel; (d) **Priority government service** — faster coordination with EPPO, ERC, PEA/MEA for interconnection.

8. 2026 updates + post-review outlook

BOI reviews incentive schemes every 3-5 years. Current cycle ends end-of-2026. Expected changes: **expanded green-tech criteria** (storage, BESS integration may be added), **category renumbering** (7.1 → 5.2.1 per draft), **utility-scale solar farms** may face 30% minimum local content. Good news for factory rooftop solar: the 8-year tax holiday structure is expected to remain. Track announcements at boi.go.th or CapSolar news.

9. 3 real scenarios — 8-year tax savings

Illustrative calculations using standard Thai CIT 20% × annual savings × 8 years. EEC bonus example: Rayong/Chonburi location.

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