Is money I earned before 2024 taxable if I transfer it to Thailand now?

The cut-off is a date of earning, not a date of arrival. That one sentence is the rule, and it helps to see where it comes from.

The two instructions, in order

Por. 161/2566, issued on 15 September 2023, changed how the remittance rule is read. For a Thai tax resident, foreign income earned from 1 January 2024 is taxable whenever it is brought into Thailand, in the same year or any later one. That closed the old gap, under which money remitted in a later calendar year than it was earned escaped entirely.

Por. 162/2566, issued on 20 November 2023, drew the line behind it. KPMG summarises it as saying the new reading should not apply to foreign income earned before 1 January 2024. That income stays under the old rule, which only taxed it if it was remitted in the year it was earned, so savings from 2023 or earlier brought in today are outside the tax. None of the sources we checked mentions a deadline for bringing that money in.

Why this is really a records question

The Revenue Department cannot see when your money was earned. You can, if you kept the evidence. What makes a claim easy to support:

1. A bank statement dated 31 December 2023 showing the balance you are now drawing on. It is the single most useful document here, so save a copy today rather than when someone asks.
2. Separate accounts: money earned before 2024 in one, money earned since in another. A mixed account turns every transfer into an argument about which baht arrived.
3. Payslips, invoices or home tax returns for the years before 2024, in case anyone asks what the balance was made of.

The mistake that costs the protection

Pooling everything in one account and topping it up with this year's invoices. Once the pot is mixed, telling pre-2024 capital from later income becomes a matter of argument rather than fact, and the burden of showing it sits with you.

None of this applies in a year where you spend fewer than 180 days in Thailand, because you are not resident and the remittance rule does not reach you. Our post on why the Thai remittance tax exemption is still not law tracks the proposal that would change the rules for later income, and the Thai tax guide for digital nomads sets out residency and remittance together.