Which Thai companies must have audited financial statements?

Every company limited registered in Thailand is required to have each year's accounts examined and signed off by a certified public accountant, approved at an ordinary shareholders' meeting held within four months of the financial year end, and submitted to the Department of Business Development. There is no small-company exemption from the audit itself, though smaller entities may use simplified reporting standards.

If you prepare our books, can you also sign the audit?

No, and you should be cautious of any arrangement where one party does both. Auditor independence rules prohibit the CPA who signs the opinion from having prepared the accounting records. Our role is to make your books audit-ready and to liaise with your appointed auditor; the opinion itself always comes from an independent CPA.

How long does a Thai statutory audit take?

Fieldwork for a straightforward SME typically runs one to three weeks once the closing schedules are complete. Delays almost always come from missing reconciliations or unlocated supporting documents, which is why the pre-audit preparation matters more than the fieldwork itself.

What does audit support cost?

The fee depends on transaction volume, the state of the current-year books and how much correction the prior periods need. Send the latest trial balance and we reply with a written scope and fee — the review itself is free of charge.

English desk

Audit support and audit-ready books in Thailand

The statutory audit in Thailand is performed by an independent CPA — that independence is a legal requirement, so the firm keeping your books cannot sign the opinion. What we provide is everything around the audit: closing schedules in the format the auditor expects, reconciled balances, supporting documents filed and indexed, and answers to the CPA's queries without the owner translating between two parties.

Request a written quote contact@thailaw-accounting.co.th

Phone +66-92-017-0000 · LINE and email accepted in English.

What this service covers

Closing schedule package

Fixed asset register, accruals, prepayments, provisions, related-party balances and bank confirmations prepared before the auditor's fieldwork starts, not during it.

Reconciled trial balance

Every balance-sheet account reconciled to evidence — bank statements, supplier statements, inventory counts — so the audit samples confirm rather than discover.

Auditor query handling

The CPA's information request list is answered by the team that prepared the books, with a log of what was sent and what remains open.

DBD and Revenue filing after sign-off

Once the opinion is signed, the statements are filed with the Department of Business Development and the annual corporate return is reconciled to them.

How the engagement runs

1. Pre-audit health check
Before the auditor arrives we review the accounts that usually generate adjustments — VAT suspense, director loans, unreconciled bank lines — and correct them in the books first.
2. Schedule preparation
Closing schedules are built to the auditor's expected format, so fieldwork is verification rather than reconstruction.
3. Fieldwork support
Queries are answered within agreed turnaround, and any proposed adjustment is explained to the owner in plain language before it is accepted.
4. Filing and next-year setup
Audited statements go to the DBD, the tax return is tied to them, and recurring audit findings are fixed in the monthly process so they do not repeat.

Deadlines, rates and filing formats change. Confirm current requirements with the Revenue Department, the Social Security Office and the Department of Business Development, or ask us to confirm them for your case before you rely on a date.

What an audit season actually demands from a Thai company

Thai law obliges every registered company to have its annual financial statements examined by an independent certified public accountant, whatever the level of activity during the year. That obligation does not disappear because the company traded very little, nor because the shareholders are all resident abroad. The auditor forms an opinion by testing balances against evidence, so the practical question facing management is never whether an audit will happen, but how much friction it will create when it does.

Friction is decided months before fieldwork. When bank accounts are reconciled each month, when supplier statements are matched rather than trusted, and when every fixed asset on the register can be pointed at in the real world, the audit becomes a confirmation exercise. When those things were postponed, the same audit turns into a reconstruction project carried out under deadline pressure, and the fee follows the hours consumed.

Our role sits on the company's side of that relationship. We assemble the schedules the auditor will request, tie each one back to its source, and keep an open log of information requests so nothing waits on a memory or an inbox. Management gets a single point of contact instead of forwarding technical questions between an auditor and a bookkeeper who have never spoken directly.

Independence is not negotiable

The firm that maintains the ledger cannot also sign the audit opinion. We prepare, the licensed auditor examines, and the separation protects the value of the report itself.

Group reporting deadlines

Subsidiaries of foreign parents usually face a group timetable that runs ahead of the local statutory one, so the closing plan is written backwards from the earlier of the two.

Prior-year adjustments

Where a previous period was misstated, the correction has to be presented properly rather than quietly absorbed, and the tax consequences assessed at the same time.

Timing, evidence and the questions auditors ask first

An audit that begins in the final weeks before the shareholder meeting is an audit conducted under duress. Fieldwork is scheduled around the availability of the audit firm, and the firms with capacity in the busiest months are the ones nobody else booked. Companies that agree a date early in the calendar year get the team they want and a schedule that leaves room for the inevitable follow-up requests. Those that wait find both the date and the fee decided for them, and any complication becomes a filing problem rather than an accounting one.

The requests that arrive first are predictable, because they test whether the reported position is real. Confirmations go to banks and to significant customers and suppliers; the fixed asset listing is compared against something physical; revenue near the year-end boundary is examined to see whether it was recorded in the correct period; and shareholder or affiliate balances are traced to an agreement. If those five areas are in order before the auditor arrives, most engagements proceed without argument.

Where a company has never been audited before, or where the previous auditor resigned, we treat the first year as a two-part exercise. The opening balances have to be established credibly, since the auditor cannot form an opinion on this year's movement without a defensible starting point. That work is done in advance and documented, because discovering the problem during fieldwork means either a qualified opinion or a delay that pushes the filing past its deadline.

What a qualified opinion costs later

Banks, prospective buyers and joint-venture partners read the opinion paragraph before anything else. A qualification stays on the public record and has to be explained in every future negotiation, which is why resolving the underlying issue before sign-off is worth the effort.

Keeping the audit file after sign-off

The schedules prepared for one audit become the comparatives for the next. We hand back an indexed pack so the following year starts from evidence rather than from a fresh reconstruction of the same balances.

Handling it in-house versus engaging us

Preparing for an audit internally is possible, but it usually falls on a finance manager who already owns month-end, payroll and the bank relationship. The schedules get written late at night, questions go unanswered for days, and the auditor bills for waiting. Bringing in a team that prepares these packages every season shortens fieldwork and keeps the report on the filing timetable rather than behind it.

Every engagement is quoted individually after we review your documents and agree the scope, so you know the fee and the timeline before any work starts. Send the details on LINE or by email and we will come back with a written proposal.

Common situations we are hired for

First audit after incorporation

Even a dormant first year requires audited statements. We prepare a clean opening set so the company's first audit establishes a reliable baseline.

Audit qualification or emphasis of matter last year

We work through the qualification point, rebuild the underlying records where possible, and document the position for the coming audit.

Group reporting deadlines

When an overseas parent needs audited Thai figures on a fixed consolidation date, the closing calendar is built backwards from that date.

Changing auditors

We manage the handover file — prior opinions, opening balances, management representations — so the incoming CPA starts from evidence, not assumptions.

See the English-speaking accounting firm overview, all accounting services or the province pages below.

Questions owners ask first

Which Thai companies must have audited financial statements?: Every company limited registered in Thailand is required to have each year's accounts examined and signed off by a certified public accountant, approved at an ordinary shareholders' meeting held within four months of the financial year end, and submitted to the Department of Business Development. There is no small-company exemption from the audit itself, though smaller entities may use simplified reporting standards.
If you prepare our books, can you also sign the audit?: No, and you should be cautious of any arrangement where one party does both. Auditor independence rules prohibit the CPA who signs the opinion from having prepared the accounting records. Our role is to make your books audit-ready and to liaise with your appointed auditor; the opinion itself always comes from an independent CPA.
How long does a Thai statutory audit take?: Fieldwork for a straightforward SME typically runs one to three weeks once the closing schedules are complete. Delays almost always come from missing reconciliations or unlocated supporting documents, which is why the pre-audit preparation matters more than the fieldwork itself.
What does audit support cost?: The fee depends on transaction volume, the state of the current-year books and how much correction the prior periods need. Send the latest trial balance and we reply with a written scope and fee — the review itself is free of charge.

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