中税泰国CTAC Thailand
Toolkit · VAT refund

Credit and refund deadline tracker: two separate clocks

In short

A refund entitlement expires on its own. Carrying input credit forward runs for six months, and anything not absorbed by then is lost; switching to a cash refund claim runs on a separate three-year period counted from the filing due date or the date of payment for that period. The two are independent — letting the credit run past six months does not mean you still have three years to claim. This workbook computes both dates for each tax period side by side, and fixes in place the step most often missed: looking at the refund box before you file.

01This is not the refund document checklist

There is a separate export VAT refund document self-check on the site. That one governs whether a claim will survive review — invoices, reconciliation, the export evidence chain. This one governs how much time is left and whether to act now. The first answers "are the documents complete"; the second answers "when to claim, and is there still time".

Used together, the order is: check the clock first, then assemble the documents.

02How the credit quietly runs past the window

This is the least visible part of the whole subject. On a monthly return, input tax exceeding output tax is carried forward to the next month by default — unless you actively tick the refund box on the last page of the return and sign it.

Which means not choosing is itself a choice. Plenty of companies have filed monthly and correctly for years without ever looking back at that box, carrying the balance forward out of habit, and discover the position only when it is already at the edge of the window. Sheet 2 exists to turn that check from "when someone remembers" into a fixed monthly question.

03The two clocks cannot be converted into each other

They are triggered differently and run separately:

The point is that neither extends the other: running past the carry-forward window does not mean there is still plenty of time to claim, and the claim period does not shift later because the credit is still within its carry-forward window. Sheet 1 puts both dates side by side so you do not read one clock and misjudge the room you have.

04Expiry is not something a late filing can repair

Once either period has run out, that part of the entitlement is gone — it is not recoverable by producing documents later or explaining the reason. The longer a historic credit sits, the more it moves from "we will get it eventually" to "we will not".

One situation is worth checking separately, though: a historic credit that is past the carry-forward window but still within the claim period may be capable of being taken through a separate claim instead. Whether that works depends on the facts and does not apply to every credit — which is exactly what sheet 3 leaves to an adviser.

05How to use it

Four steps, in this order:

Amber cells need an adviser's confirmation; blank cells are yours. The specific window lengths, how they are counted and when they apply are governed by the Revenue Department's rules as currently published; this workbook does not replace checking period by period.

What is in the workbook

  • The two clocks compared (nothing to fill in — read it first): how each is triggered, when it starts, how long it runs, what happens on expiry, and the most common way each is missed
  • Credit ledger: balance by tax period, start date, carry-forward expiry and claim-period expiry, with status visible at a glance
  • The monthly pre-filing question: turning "look back at the refund box" into a fixed step — not choosing is itself a choice
  • Whether to claim: seven factors side by side (expected output tax, room left on each clock, scope to rescue a historic credit, document status, cash flow, filing anomalies)
  • Designed to be used with the refund document self-check: check the clock first, then assemble the documents

Download

Editable workbook (XLSX)
The workbook itself is in Chinese — the column headings carry the Thai form names, so it is usable alongside this page. Ask our advisers if you would like it walked through.

Common questions

The credit is already past the carry-forward window. Is the money gone?

Not necessarily. A historic credit that is past the carry-forward window but still within the claim period may be capable of being taken through a separate claim. Whether that works depends on the facts and does not apply to every credit, so it has to be checked period by period against your filing record. Where both periods have run out, that part of the entitlement is genuinely lost — documents or explanations will not bring it back.

We have filed monthly and correctly for years. How could we still miss it?

Because filing correctly is exactly what carries the credit forward. The excess of input over output goes to the next month by default unless you tick the refund box on the last page and sign. Filing punctually and looking back at that box are two different things.

Will claiming cash back attract a review?

A claim goes into a review process, and the documents and reconciliation will be examined. That is not a reason not to claim — it is a reason to self-check before claiming. The refund document self-check on the site is built for exactly that. Check the clock to decide whether to act, then use that one to go through the documents.

What are the actual periods?

Our article on carrying credit forward against claiming cash back sets them out in full. But the windows, how they are counted and when they apply are governed by the Revenue Department's rules as currently published, and they have to be computed period by period from your actual filing due date or payment date — which is why the start date in the workbook is a cell that needs confirming rather than assuming.

Related

Sources

  1. Thailand Revenue Code Section 84 (rules on excess input credit and refunds), via the Revenue Department: where input tax exceeds output tax the difference may be carried forward to the following period or claimed as a refund as provided; input credit may be carried forward for six months only, and a separate cash refund must be claimed within three years from the filing due date (or the date of payment) for the corresponding tax period. Checked 2026-06; each period governed by the Revenue Department's rules as currently published.
  2. General note: the carry-forward window for input credit, the separate period for claiming a cash refund and its starting point (the filing due date or the date of payment for that tax period), and the circumstances in which a historic credit may instead be taken through a separate claim, are all governed by the Thai Revenue Department as currently published; the treatment whereby input exceeding output on a monthly return is carried forward by default unless the refund box on the return is actively ticked follows the return format and rules as currently published. This toolkit states no day counts or amounts; an individual case must be confirmed by our advisers period by period against the actual filing and payment record.
Checked against the official texts by the CTAC Thailand advisory team. We track the gazettes of the BOI, the Revenue Department, the Department of Business Development and Thai Customs every week; when an official position changes, the affected pages are updated and dated.
This page is general information based on the rules in force at the date shown. Thai BOI categories, incentive conditions and foreign-investment rules change often. Before acting on any specific project, check the latest official announcement and have a formal opinion issued on your own facts.
Bring us the periods the tracker flags

Whether a historic credit can still be rescued, and in what order, depends on your filing record.

中文版 · Chinese version