For business owners in Chiang Mai, the first quarter through May each year is the key period for preparing and submitting annual financial statements. But if you are facing a situation where your accounting firm cannot be reached, calls go unanswered, LINE messages go unread, tax documents are piling up and the deadline for filing the 2026 annual financial statements is approaching, staying calm and following the correct process is the most urgent thing you can do. This problem can be resolved under the rules of the Department of Business Development (DBD) and the Revenue Department, so that the company and its directors do not end up bearing statutory fines.
This article sets out a step-by-step approach, a table of deadlines and fines under the latest law, and a worked tax calculation from a real case, so that business owners can recover from an accounting crisis and close their financial statements in time.
Year-end close deadlines and the legal consequences when your accounting firm cannot be reached
Legally, the fact that your previous bookkeeper abandoned the work, lost contact or failed to hand over cannot be used as grounds to request an extension for filing financial statements or tax returns with government agencies. Business owners therefore need to know the exact time frames and penalties.
1. Deadlines under the Accounting Act B.E. 2543 (2000) and the Civil and Commercial Code (Department of Business Development)
For juristic persons with an accounting period ending 31 December 2025, the law sets the following steps and deadlines for the 2026 cycle:
- Hold the annual general meeting of shareholders (AGM): the meeting must be held within 4 months of the end of the accounting period, that is by 30 April 2026. The notice of the meeting must be sent by registered post with acknowledgement of receipt or published in a local newspaper under Section 1175 of the Civil and Commercial Code at least 7 days in advance (or 14 days for a special resolution).
- Submit the shareholder list (Bor.Or.Jor.5): must be filed with the Department of Business Development within 14 days of the AGM.
- File the financial statements with the Department of Business Development (DBD): the financial statements, audited and certified by a certified public accountant (CPA), must be filed through DBD e-Filing within 1 month of the AGM, or by 31 May 2026.
2. Deadlines under the Revenue Code (Revenue Department)
Under Sections 68 and 69 of the Revenue Code, a juristic person must file its annual corporate income tax return (P.N.D.50) together with the financial statements within 150 days of the end of the accounting period:
- Paper filing deadline: by 30 May 2026
- Online filing deadline: filing through the Revenue Department e-Filing system gives an extra 8 days to file and pay, under a Ministry of Finance notification
Comparison table of fines for late financial statements and tax filings
| Offence | Agency | Deadline (31 Dec year-end) | Statutory fines and penalties |
|---|---|---|---|
| Financial statements filed up to 2 months late | Department of Business Development (DBD) | June – July 2026 | Fine of 2,000 baht for the company and 2,000 baht for the authorised director (4,000 baht in total) |
| Financial statements filed more than 2 but not more than 4 months late | Department of Business Development (DBD) | August – September 2026 | Fine of 8,000 baht for the company and 8,000 baht for the authorised director (16,000 baht in total) |
| Financial statements filed more than 4 months late, or not filed | Department of Business Development (DBD) | From October 2026 onwards | Fine of 12,000 baht for the company and 12,000 baht for the director (24,000 baht in total); if a summons is issued, up to 50,000 baht for each party |
| P.N.D.50 filed late | Revenue Department | More than 150 days after the year-end | Up to 7 days late: fine of 1,000 baht / more than 7 days: fine of 2,000 baht under Section 35 of the Revenue Code |
| Surcharge on unpaid tax | Revenue Department | From the day after the payment due date | Surcharge of 1.5% per month (a fraction of a month counts as a full month) under Section 27 of the Revenue Code |
4 steps to recover when your accounting firm cannot be reached and the deadline is near
Once it is clear that the accounting firm cannot be reached or has abandoned the work, the authorised signatory must take control of the data and documents immediately by following these 4 steps:
- Gather all accounting and financial documents held by the business: Request bank statements for every account in the company's name for the full 12 months (January – December 2025) as PDF and Excel files from online banking, and collect copies of receipts, sales tax invoices, purchase tax invoices, withholding tax certificates (50 Tawi), loan agreements, lease agreements and payroll records.
- Check the tax filing history in the Revenue Department's e-Filing system: Log in with the company's own user ID to check up to which month the previous firm filed the monthly returns (P.P.30, P.N.D.1, P.N.D.3, P.N.D.53) and whether the half-year return (P.N.D.51) was filed. This tells the new bookkeeper exactly where the records stop, so they can pick up immediately without recording anything twice.
- Send a formal letter terminating the contract and demanding the documents: Prepare a letter terminating the engagement and requesting the return of all accounting records, journals and supporting documents, and send it by registered EMS with acknowledgement of receipt to the previous firm's registered address. The acknowledgement serves as evidence of the directors' good faith towards the Department of Business Development and the Revenue Department, or as evidence when filing a police report.
- Hand over to a new accounting firm and coordinate with the auditor (CPA) urgently: Choose an accounting firm with enough staff to import the prior year trial balance and speed up the account reconciliations, and with a network of certified public accountants ready to examine the evidence and sign off the financial statements before the end of May.
Real-world example: a cafe and hostel in the Nimman area of Chiang Mai clears its accounts urgently
To illustrate how the tax is assessed and the damage contained, consider this example modelled on a real case of a business in Chiang Mai:
Nimman Cozy Co., Ltd. runs a cafe and guest rooms in the Nimmanhaemin area, with registered capital of 1,000,000 baht and an accounting period ending 31 December 2025. Total revenue for the year was 3,600,000 baht. In March 2026 it emerged that the accounting firm could not be reached; the documents for the last 4 months (September – December) had not been recorded and no trial balance had been prepared.
Steps for calculating corporate income tax:
- Total revenue for the year: 3,600,000 baht
- Cost of sales, administrative expenses and substantiated depreciation: 2,800,000 baht
- Accounting net profit before adjustments:
3,600,000 - 2,800,000 = 800,000 baht - Add back non-deductible expenses under Section 65 ter of the Revenue Code: 50,000 baht (for example, expense documents with no evidence of the payee, or incomplete tax invoices)
- Net profit for tax calculation:
800,000 + 50,000 = 850,000 baht
Tax calculation at the SME corporate income tax rates (capital not exceeding 5 million baht and revenue not exceeding 30 million baht):
- First 0 – 300,000 baht of net profit: exempt from tax (0 baht)
- Net profit above 300,000 up to 850,000 baht (tax base 550,000 baht) at the 15% rate:
550,000 x 15% = 82,500 baht - Less withholding tax already deducted (P.N.D.53 / 50 Tawi certificates collected): 12,500 baht
- Corporate income tax actually payable:
82,500 - 12,500 = 70,000 baht
Assessing the damage if nothing is done: if the P.N.D.50 ends up being filed 2 months late, the business will pay a criminal fine for late filing of 2,000 baht plus a surcharge of 1.5% per month, 70,000 x 1.5% x 2 months = 2,100 baht, and if the financial statements are filed with the DBD more than 2 months late, the company and the director will face a further combined fine of 16,000 baht.
By switching to a new bookkeeper and catching up on the backlog so that the tax return and financial statements could be filed by May 2026, the company saved more than 20,100 baht in fines and surcharges.
Choose accounting services in Chiang Mai from YMTD to restore your accounting system safely and worry-free
If you are looking for a specialist ready to take over when your previous accounting firm has abandoned the work, choosing a provider of accounting services in Chiang Mai that is transparent and works systematically removes all of that worry.
YMTD Accounting Partner works in a way designed specifically for modern businesses in Chiang Mai:
- Works on an online accounting system: records are kept systematically, the data is secure and cannot be lost, and work can be handed over smoothly
- Sends and receives documents digitally: business owners do not have to spend time travelling to deliver paper documents; simply photograph or scan them and send them digitally, and the team records them promptly
- Communicates via LINE, quickly and conveniently: a direct channel to the team, easy to reach, never goes silent, and answers tax questions in plain language, like "the tax teacher next door"
- Offers a fully connected service: monthly bookkeeping, proper tax planning, and coordination with the audit team of certified public accountants (CPA)
- Supports your front-of-house system: for shops, restaurants and cafes in Chiang Mai, we provide a point-of-sale (POS) program with stock management, worth 15,000 baht, free of charge with our monthly accounting service. It is installed and taught on site, the data is stored on your own machine, and it is secure and works offline
How to hand over documents and start working with YMTD Chiang Mai
Business owners who need to change accounting firm or hand over urgently can follow these simple steps:
- Contact us and tell us where the documents stand: add us on LINE or call to talk it through, so we can assess which month the backlog goes back to and when the filing deadline is
- Send the files and digital documents: send copies of the tax returns already filed and the outstanding income and expense documents through our online channel
- The team starts clearing the backlog: entering the transactions into the online accounting system, reconciling the bank accounts and preparing the trial balance
- Audit and filing: coordinating with the certified public accountant to issue the audit report, and filing the financial statements with the DBD and the Revenue Department completely and correctly
Frequently asked questions
What if the previous accounting firm refuses to return documents or cannot be reached at all?
Send a letter terminating the contract and demanding the documents by registered post with acknowledgement of receipt (EMS). If there is no response, take the acknowledgement slip to the police and have the matter recorded as evidence. The business owner can then request copies of past tax returns from the Area Revenue Office, request past statements from the bank, and download the previous year's financial statements from DBD e-Filing so that the new bookkeeper can use them as opening balances and start recording straight away.
If the previous firm has not yet removed its name as bookkeeper in the DBD system, can the new bookkeeper file the financial statements?
Yes. The new bookkeeper can register as the juristic person's bookkeeper directly through the Department of Business Development's e-Accountant system, or the authorised director can sign an appointment of the new bookkeeper and notify the change in the system in order to file the annual financial statements under the DBD rules.
If the deadline is near but the financial statements are not finished, should you file P.N.D.50 or the DBD financial statements first?
Priority should go to filing the P.N.D.50 and paying the corporate income tax to the Revenue Department within the 150-day deadline (using the closest possible estimate of taxable net profit), to stop the 1.5% monthly surcharge from accruing and reduce the criminal fine. Then, once the auditor has completed the audit of the financial statements, file them with the DBD, and if the tax figure differs, file an additional (amended) P.N.D.50 later.
If some documents were lost with the previous accounting firm, will the auditor (CPA) certify the financial statements?
The auditor will assess how material the missing documents are. If the items do not have a material effect on the financial statements, or alternative evidence such as bank statements and confirmations from trading partners can be used instead, the CPA will issue an unqualified audit report. If a large amount of key documentation is missing, the CPA may issue a qualified opinion or a disclaimer of opinion. Financial statements with this kind of audit report can still legally be filed with the DBD and the Revenue Department to avoid the fine for non-filing.
Summary: do not let your business stall; get the year-end close done correctly and on time
Finding that your accounting firm cannot be reached at a critical time is worrying, but what matters most is to act step by step, gather the documents you still have, and choose a professional provider of accounting services in Chiang Mai to take over and bring the accounts into line with official requirements.
If you are facing this problem and want an adviser who will look after you closely, contact YMTD Accounting Partner Chiang Mai right away. The team is ready to check your documents and plan the year-end close so that you meet the deadline.
Urgent consultation and accounting handover:
Tel: 081-542-3019
LINE: @premwittawat
YMTD Accounting Partner Chiang Mai — with your business at every step
