RMF vs Thai ESG: What Still Counts for Your Thai Tax Deduction in 2026

The RMF limit is shared with provident funds

Contributions to RMF and to a provident fund are deductible together, up to ฿500,000 a year and no more than 30% of your assessable income. If your employer already takes a provident fund contribution from your pay, that counts toward the same limit, so add it up before you buy.

RMF units must be held until you turn 55. Holding rules have been adjusted over the years, so confirm the current conditions with your fund provider before you commit money you may need earlier.

Thai ESG has its own limit

Thai ESG funds are deductible up to ฿300,000 and 30% of income, separate from the RMF limit, for purchases made from 1 January 2024 to 31 December 2026. That separate limit means you can use both: RMF and provident fund up to their shared ฿500,000, and Thai ESG on top up to ฿300,000, each within 30% of income. Thai ESG units carry their own holding-period conditions, so check them with the fund provider.

Side by side

What is verified and what to confirm with a provider:

• Deduction limit: RMF shares ฿500,000 with provident fund; Thai ESG has its own ฿300,000. Each is also capped at 30% of income.
• Purchase window: Thai ESG applies to purchases through 31 December 2026, so its deadline is this year; we have not found an end date for RMF, but check with your provider.
• Holding period: RMF until age 55; Thai ESG has its own conditions. Confirm both with the fund provider before buying.
• SSF: no deduction for purchases from 1 January 2025.

A worked example

Take someone with ฿600,000 of income and no other deductions beyond the automatic ones. Their taxable income is ฿440,000 and their tax is ฿21,500. Their 30% limit is ฿180,000, so that is the most they can put into RMF.

• An extra ฿100,000 in RMF brings taxable income down to ฿340,000 and tax down to ฿11,500 — a saving of ฿10,000.
• An extra ฿150,000 brings taxable income to ฿290,000 and tax to ฿7,000 — a saving of ฿14,500, and they drop from the 10% bracket into the 5% bracket.

Notice the saving is ฿14,500 rather than ฿15,000 (฿150,000 × 10%): once part of the deduction pulls income into a lower bracket, the last baht is worth 5%, not 10%. The Taxolase simulator recalculates the tax each time, so it shows the real saving rather than a rate multiplied by an amount.

A higher-income example

Now take ฿1,200,000 of income. After the automatic deductions, taxable income is ฿1,040,000 and tax is ฿125,000, with a marginal rate of 25%. An RMF purchase of ฿200,000 (within the 30% limit of ฿360,000) brings taxable income to ฿840,000 and tax to ฿83,000, a saving of ฿42,000.

That is 21% of the amount invested, not 25%: the first ฿40,000 of the deduction removes income taxed at 25% (฿10,000) and the remaining ฿160,000 removes income taxed at 20% (฿32,000). The higher your bracket, the more a deduction saves, which is why these funds matter most to higher earners.

Mistakes to avoid

The same few errors come up every year:

• Buying more than the 30%-of-income limit allows, so part of the purchase earns no deduction.
• Forgetting that provident fund contributions from your salary count toward the RMF limit.
• Waiting until the last week of December, when the Thai ESG window for 2026 closes on 31 December.
• Buying purely for the tax saving without a plan for the holding period, then needing the money early.

Before you buy

A deduction is not free money: you are locking savings into an investment that can lose value, for a period the rules set. The tax saved is real, but it only makes sense if you would be comfortable holding the fund anyway. Use the simulator on the Advisory step to see the saving at your own income, and check the holding rules with your fund provider.