What are the main filing deadlines for a Thai company?

Withholding returns by the 7th of the following month, VAT by the 15th, half-year corporate tax within two months after the first six months, the annual corporate return within 150 days of the financial year end, and audited statements filed with the DBD after the shareholders' meeting. E-filing adds a short extension to most monthly deadlines. Confirm current dates with the Revenue Department as rules are adjusted from time to time.

What does a late filing actually cost?

Surcharge runs at 1.5 percent per month on the tax due, plus fixed penalties per return, and criminal fines apply in some cases. On a nil return the cost is the penalty alone; on a large VAT month it compounds quickly.

Can you file for past years?

Yes. Back-period filing starts from bank statements and invoices where the ledger no longer exists, and we advise on the order of filing to manage the surcharge exposure.

What does the service cost?

Monthly filing work is quoted by return types and transaction volume; annual returns by complexity. Send your filing status and we reply with a written quote — the review is free.

English desk

Tax filing services in Thailand — corporate, VAT and withholding

A Thai company's filing calendar never stops: withholding returns by the 7th, VAT by the 15th, half-year corporate tax within two months of mid-year, the annual PND.50 within 150 days of year end, and personal returns for directors and employees each March. Missed deadlines cost surcharge and penalty calculated on the tax due, so the practical value of a filing service is a calendar that is never late.

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

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

What this service covers

Corporate income tax returns

The half-year PND.51 estimated from actual results, and the annual PND.50 reconciled to the audited financial statements with the tax adjustment computation documented.

Monthly withholding returns

PP.53 and PP.3 for services, rent and supplier payments, and PP.1 for employment income, with certificates issued to payees correctly and on time.

VAT returns

Monthly PP.30 prepared from the invoice ledgers, and specific business tax returns where they apply instead.

Personal income tax support

Annual PND.90/91 preparation for directors and employees, reconciled to the payroll records and withholding certificates.

How the engagement runs

1. Filing status review
We list every return type the company owes and check the filing history, because inherited missed periods must be caught before they are discovered.
2. Calendar setup
Every deadline is mapped for the year, with document cut-off dates agreed so filings are never assembled at the deadline.
3. Preparation and filing
Each return is prepared from the ledger, reviewed, and filed electronically, with the receipt archived.
4. Confirmation and archive
You receive confirmation of each filing and an organised archive of receipts — the file the Revenue Department asks for first in any review.

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.

The Thai filing calendar, and why it defeats good intentions

A single operating company can face dozens of submission dates in a year: monthly indirect tax, several categories of withholding, social security, a half-year corporate estimate and the annual return, each with its own form and its own consequences for lateness. The problem is not that any one of them is difficult; it is that they arrive continuously while the business is doing something else.

We solve it structurally by building a calendar specific to the company, working to that calendar in advance, and reconciling each return to the accounting records before it is submitted. Sales declared for indirect tax that do not agree with reported revenue is one of the clearest triggers for selection, so where a difference genuinely exists we record the reason in the file at the time rather than trying to reconstruct it later.

After submission the evidence has to survive. Payment receipts, filed forms and the computations behind them are archived by tax year, because examinations frequently begin long after the staff who handled the filing have left the company. A file that explains itself is worth more at that moment than any recollection.

The half-year estimate

Understating projected profit beyond the statutory tolerance carries a penalty, so the estimate is built from actual results plus a defensible trend rather than copied from the prior year.

Withholding certificates

Every deduction needs a certificate issued to the payee; without it the counterparty cannot take the credit and the disagreement returns as a commercial problem.

Voluntary correction

Amending a return before an inquiry begins costs materially less than being assessed, which is why we review prior periods when we take on a new client.

Reconciliation, evidence and dealing with an inquiry

The value of a filing service is not in submitting forms; it is in ensuring that everything submitted can be reconciled to everything else. Revenue declared for indirect tax over twelve months should agree with revenue in the audited statements. Wages reported for withholding should agree with what social security shows and with payroll expense in the ledger. Payments to service providers on which tax was withheld should match the expense accounts they were charged to. Where those comparisons do not agree, we identify why before submission and record the reason.

When an inquiry does arrive, the response determines how long it lasts. A prompt reply that answers the specific question, references the underlying document and provides a clean copy usually closes the matter. A partial answer invites a broader request. We prepare responses on the company's behalf, keep a record of what was provided, and involve the owner only where a commercial decision is genuinely needed rather than forwarding every letter.

Businesses that trade across borders add a further reconciliation. Amounts invoiced in another currency are reported in baht at a rate that has to be applied consistently, service fees paid to suppliers outside Thailand may create an obligation to account for tax on the recipient's behalf, and shipments have customs values that ought to correspond to what the purchase ledger records. Where those three sources disagree the difference is visible to anyone comparing them, so we align them as part of the filing routine rather than waiting for someone else to notice.

Companies coming to us with unfiled periods are handled without drama. We establish what is outstanding, quantify the likely surcharge and penalty for each period, and file in a sequence that limits the exposure while remaining affordable. Correcting voluntarily is consistently treated more favourably than being found, and knowing the number in advance is what allows an owner to plan rather than avoid the subject.

Payments and proof

A submitted return without a matching payment record is an open liability. Every filing in our archive is stored together with the receipt, indexed by tax year.

Authority to act

Filing on your behalf requires a properly executed authorisation, which we prepare with the engagement so no deadline is missed while paperwork circulates.

Handling it in-house versus engaging us

Electronic filing systems make submission feel simple, and it is — until one return is missed and surcharge begins accruing on top of a penalty calculated from the tax due. The person responsible is usually also serving customers. Handing the calendar to a team whose only job is meeting it removes the single most avoidable cost in Thai compliance.

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

Returns that were missed or filed late

We quantify surcharge and penalty exposure, file the open periods, and set the calendar so the position does not recur.

A company whose accountant left suddenly

We recover the e-filing credentials and filing history, then close the open months before the next deadline passes.

Half-year tax on a growing business

PND.51 based on a realistic estimate rather than a guess avoids both underpayment surcharge and cash parked unnecessarily with the Revenue Department.

Foreign directors needing personal returns

Employment income paid in Thailand is taxable here; we prepare the personal return consistent with the company payroll records.

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

Questions owners ask first

What are the main filing deadlines for a Thai company?: Withholding returns by the 7th of the following month, VAT by the 15th, half-year corporate tax within two months after the first six months, the annual corporate return within 150 days of the financial year end, and audited statements filed with the DBD after the shareholders' meeting. E-filing adds a short extension to most monthly deadlines. Confirm current dates with the Revenue Department as rules are adjusted from time to time.
What does a late filing actually cost?: Surcharge runs at 1.5 percent per month on the tax due, plus fixed penalties per return, and criminal fines apply in some cases. On a nil return the cost is the penalty alone; on a large VAT month it compounds quickly.
Can you file for past years?: Yes. Back-period filing starts from bank statements and invoices where the ledger no longer exists, and we advise on the order of filing to manage the surcharge exposure.
What does the service cost?: Monthly filing work is quoted by return types and transaction volume; annual returns by complexity. Send your filing status and we reply with a written quote — the review is free.

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