Starting and running a business in Thailand is an exciting opportunity, but many foreign investors quickly realize that accounting and tax compliance can be one of the trickiest parts of doing business here. Thai accounting rules are detailed, deadlines are strict, and penalties for mistakes can be costly.

At Lex Bangkok, we often receive questions from expats, entrepreneurs, and international companies about accounting requirements in Thailand. This guide answers the most common questions foreigners ask.

After Company Registration: The Next Step

Once you have successfully set up a company in Thailand, the very next step is to put an accounting system in place. By law, every company must maintain proper bookkeeping, submit monthly tax filings, and prepare audited financial statements, even if the business has not yet started operations.

This means accounting is not optional, it is a mandatory requirement that begins immediately after company registration.

Do I Need Accounting Services in Thailand as a Foreigner?

Yes. Every company registered in Thailand is required to keep proper accounts, even if it has no income or activity. Financial statements must be prepared in Thai, filed with the Revenue Department and Department of Business Development (DBD), and audited annually by a licensed auditor.

This means that even a holding company or representative office must maintain compliance. Many foreigners hire local accountants to make sure everything is done correctly.

What Are the Main Accounting Requirements in Thailand?

Foreigners usually ask us about three main areas:

1. 1. Bookkeeping – Recording monthly income, expenses, invoices, and transactions.
   2. Tax Filings – Submitting VAT, corporate income tax, and withholding tax on time.
   3. Annual Audit & Reports – Every company must submit audited financial statements to the DBD within five months after year-end.

Do I Need to File VAT in Thailand?

If your company earns more than 1.8 million THB per year, VAT registration is mandatory. Once registered, you must file monthly VAT returns, even if you had no activity in that period.

Many foreign clients are surprised to learn that non-compliance can result in significant fines, which is why outsourcing VAT filings is a common request.

How Much Do Accounting Services Cost in Thailand?

Accounting fees usually depend on:

• • Transaction volume (how many invoices per month)

• • Company size (startup vs. established business)

• • Services required (bookkeeping only, or full package with payroll + tax)

At Lex Bangkok, we offer transparent, scalable packages, so startups don’t overpay and larger companies get the support they need.

Common Mistakes Foreigners Make

• • Thinking accounting is optional if there’s no income.

• • Missing monthly tax filing deadlines.

• • Not keeping receipts and documents in Thai format.

• • Hiring unlicensed accountants.

Avoiding these mistakes can save you money and protect your business reputation.