RMF vs Thai ESG in 2026: caps, lock-ups, and why this year is different

Thailand offers two mutual fund deductions to individual taxpayers in 2026. RMF, the retirement fund, has been around since 2001 and locks your money until you're 55. Thai ESG is newer, locks money for five years, and for purchases made through 31 December 2026 carries a ฿300,000 cap that reverts to ฿100,000 and an eight-year hold in 2027, unless the government extends it. It hasn't, as of this writing.

That makes 2026 a decision year. This guide lays out the rules for both, works through what a typical salaried taxpayer can claim, and describes a common order of operations under current caps. It applies to anyone who files a Thai return, foreign or Thai; the eligibility section covers what changes for foreigners.

The two funds side by side

RMF in detail

The deduction is 30% of assessable income up to ฿500,000, but that ฿500,000 is shared with your provident fund contributions, any GPF, pension (annuity) insurance, and the National Savings Fund. Someone contributing ฿100,000 to a provident fund has ฿400,000 of RMF room at most. The Revenue Department's deduction summary (Thai) lists both caps.

The old minimum purchase (3% of income or ฿5,000) was abolished in 2020. You can put in ฿1,000 in a thin year to keep continuity. Continuity means buying in at least every other year; two consecutive blank years break the chain.

The lock is the real cost. You can't redeem without penalty until you're 55 and at least five years have passed since your first RMF purchase. For a 35-year-old that's a 20-year commitment. Sell early and you repay every deduction you claimed in the previous five years — all of them, if you held under five years — with a 1.5% monthly surcharge from April of the following year, and the gains become taxable. Switching between RMF funds, at the same or a different manager, isn't a redemption and is unlimited, so you can change strategy without breaking anything. The holding rules are in Director-General Notification No. 401 (Thai).

One consolation: once the first lot passes five years and you're 55, everything in the RMF is redeemable, including units bought last month.

Thai ESG in detail

For purchases from 1 January 2024 to 31 December 2026, the deduction is 30% of assessable income up to ฿300,000, on top of the RMF group. There's no continuity requirement; buy once and never again if you like. The terms are in Director-General Notification No. 442 (Thai), announced in Revenue Department press release 24/2567.

Each purchase carries its own five-year clock, counted day to day, not by calendar year. Units bought on 30 December 2026 become free around 30 December 2031; check how your fund manager counts the last day. Sell a lot early and you repay the tax saved on that lot, plus the 1.5% monthly surcharge, and pay tax on the gain.

From 1 January 2027 the fund reverts to its original terms under Ministerial Regulation 390: a ฿100,000 cap and an eight-year hold, running to 2032. No extension of the 2024–2026 terms has been gazetted or formally proposed. The Finance Minister has said publicly he considers this style of incentive distorting, and the ministry's attention is on TISA, a savings account scheme with a single combined cap (฿600,000 in the July 2026 reports, ฿800,000 in December 2025's), targeted for Cabinet in September 2026 and not yet law. Any of that could change between publication and 30 December. The rules above are the ones in force today.

Thai ESGX, the one-off 2025 scheme, closed its subscription window on 30 June 2025. If you switched old LTF units into it, ฿50,000 of the switch is deductible in each of 2026 through 2029 automatically. Nothing to buy.

Can a foreigner claim these?

The regulations contain no nationality condition. The deductions belong to any individual with assessable income who files a Thai return. Expat tax advisers confirm foreigners with Thai income use both funds routinely.

The obstacles are practical. Fund account opening is a KYC matter at each asset management company, and most want a passport, a long-stay visa, a second government ID (usually a work permit), Thai address proof, and a Thai phone number. App-only onboarding often rejects non-Thai IDs; a branch visit works. You also need a 13-digit Thai tax ID, because since 2022 the fund manager reports your purchases to the Revenue Department electronically, keyed on that number, and you have to give each manager one-time consent to do so. No consent, no deduction.

US persons face two extra problems. Some managers decline US clients under FATCA, so check before you open. And both funds are almost certainly PFICs for US tax purposes, so the Thai saving may be eaten by US reporting. Talk to a US-side adviser first.

Anyone who might leave Thailand before 55 should think hard about RMF. Leaving doesn't force a sale, but if you later need the money, the penalty is the same as for anyone else.

Worked example: ฿1,200,000 salary

Assessable employment income ฿1,200,000. Provident fund contribution 5%, or ฿60,000. Social security ฿10,500 (the 2026 maximum). No pension insurance.

Thirty percent of income is ฿360,000. That's the ceiling for each fund before the caps.

RMF room: ฿360,000, checked against the shared ฿500,000 cap — ฿360,000 plus ฿60,000 provident fund is ฿420,000, under the cap, so room stays at ฿360,000. Thai ESG room: ฿360,000, capped at ฿300,000.

Tax without either fund: income ฿1,200,000, less ฿100,000 expenses, ฿60,000 personal allowance, ฿60,000 provident fund, ฿10,500 social security. Net ฿969,500. Tax ฿108,900.

Tax with RMF ฿360,000 and Thai ESG ฿300,000: net ฿309,500. Tax ฿8,450. Saving ฿100,450 on ฿660,000 invested.

That's the headline number. The more useful one is the saving per baht at each step, because the deductions come off the top bracket first:

The last ฿190,500 saves only 10%, with the same five- or twenty-year lock as the first. At this income, ฿400,000 to ฿450,000 across both funds captures most of the benefit. Maxing both is rarely the right answer unless you'd have invested the money anyway and the lock-up doesn't bother you.

A common order of operations under current caps

A common order of operations under current caps is Thai ESG up to the ฿300,000 cap or 30% of income, whichever is lower. The reasons people give: the shortest lock (five years), no continuity obligation, a separate cap so the RMF room stays intact, and a limit that drops by two-thirds from 2027 on current law. The downside is investment scope. Thai ESG funds hold Thai sustainability-screened stocks and green bonds, and the SET has had a poor decade. A five-year deduction of 20% cushions a lot of underperformance, but not all of it.

In that same order, RMF comes next, sized to the slice that would save tax at 15% or above, and only for someone who expects to be in Thailand, or to leave the money locked, until 55. RMF can hold global equity, gold, or bonds, which is why people who will still be here at 55 often use it for the longer holding period.

Pension insurance sits last in that sequence, for whatever is left of the ฿500,000 combined ceiling. It is the least liquid of the three and the hardest to leave.

Mechanics and deadlines

The cut-off is Wednesday 30 December 2026; the 31st is a public holiday. Orders execute at that day's NAV, and managers close their books for tax funds early on the last day, some at 13:00. Place orders by 24 December and you won't be refreshing an app on New Year's Eve.

Give consent to share data with the Revenue Department in each manager's app the first time you buy. It's a one-time checkbox, usually worded something like "declaring intent to use the tax deduction right". When you e-file in March, the purchase figure is pre-filled from what the managers reported; you can edit it down but not up. The Revenue Department describes this reporting (Thai).

Don't over-buy. Units above your entitlement give no deduction but carry the same lock, and selling them early is treated as a violation.

Keep the purchase confirmations. ThaiWealth AI's deduction tracker holds your RMF purchases alongside insurance premiums and donations, so you're not hunting for them in March. Thai ESG and mortgage interest aren't tracked yet.

Frequently asked questions

Is 2026 the last year for the Thai ESG ฿300,000 deduction?

Under current law, yes. Purchases from 1 January 2027 revert to a ฿100,000 cap with an eight-year hold. No extension has been gazetted as of this writing.

Can I still deduct SSF in 2026?

No. SSF purchases stopped qualifying after 31 December 2024. Units bought earlier keep their ten-year holding condition.

What happens if I sell RMF before 55?

You repay the deductions claimed in the previous five years — all of them if held under five years — pay a 1.5% per month surcharge from April of the following year, and the gains become taxable income. Switching between RMF funds doesn't trigger this.

Does the RMF ฿500,000 cap include my provident fund?

Yes. RMF, provident fund, GPF, pension insurance, and the National Savings Fund share a combined ฿500,000 ceiling. Thai ESG is separate.

Can foreigners claim RMF and Thai ESG deductions?

Yes, if they file a Thai return with assessable income and have a Thai tax ID. The hurdle is opening the fund account, which usually needs a work permit or other second ID, and giving the fund manager consent to report to the Revenue Department.

What is TISA and does it replace these funds?

TISA is a proposed savings account with one combined deduction cap across funds and other instruments. It was approved in principle in December 2025 and, as of this writing, is still being finalised. It hasn't replaced RMF or Thai ESG, and its effective date is unconfirmed.