Thai tax and accounting laws can sometimes be difficult to understand, particularly if you are not familiar with the Thai language. At Optimum, we provide clear and transparent services for all of your tax and accounting needs in a way that not only completes all obligations and meets the highest standards of compliance, but takes care of your business requirements, manages risk and anticipates the impact of regulatory developments.

At Optimum, we provide clear and transparent services for all your tax and accounting needs.


Under Thai law, all businesses must pay income tax on income earned from sources in and outside of Thailand. Optimum’s team of qualified accountants are on hand to help you with all of your taxation requirements and communications with the Thai Revenue Department. Our team has a detailed understanding of local laws, policies and working conditions as well as extensive knowledge of professional standards and practices, to provide you with a hassle-free, personalized service.

Our taxation services include:

Tax advisory, tax planning, tax return preparation and helping you fully understand all tax concerns and compliance matters

Coordinate with and confront the government tax examination team if they contact or visit you

Prepare and submit tax applications as required by Thai tax law


A qualified Thai accountant must complete all accounts in Thailand, according to the Accounting Act B.E. 2543 (2000), legislation that applies to all businesses in the country. At Optimum, you’ll be provided with a team of qualified Thai accountants to take care of all your needs as required by Thai accounting law. We can create tailored reports with transaction details for each account, depending on your individual needs.

Our accounting services include:

Reconciliation statement of an account

Verifying and analyzing accounting transactions

Planning and design monthly management financial reports

Annual and monthly financial statements and reporting packages

Preparing and reviewing consolidation statements

Reconciling Thai GAAPs and IFRS

Coordinating with independent auditors


Optimum’s bookkeeping service gives you insights into your company’s financial health and helps you operate with clean books throughout the year. As well as helping your business with every aspect of the accounting process, we offer individual bookkeeping services if you need assistance with just one or two aspects of your accounting needs.

Adhering to Thailand accounting standards to the highest level, our bookkeeping services include:

Accounts receivable

Account payable

Fixed asset register

Inventory reports and stock cards

Reconciliation of bank statements


Optimum handles every aspect of your payroll process whilst ensuring total confidentiality, meaning you don’t have to worry about missing important deadlines or falling short of Thai accounting laws and practices. With our significant experience in Thai payroll, we give you the support you need to be compliant, make the right decisions and have peace of mind.

Our payroll services include:

Calculation of personal tax liability according to the company calendar

Preparation of batch payment direct deposits through employee’s bank accounts

Preparation and issuance of payroll slips

Monthly tax filings (PND.1, staff withholding tax report)

Preparation and filing of Social Security Fund reports on a monthly and annual basis as required by the law

Administrative Service

Under Thai law, certain documents need to be correctly completed for invoices, tax invoices and receipts. All billing documentation must adhere to strict rules and regulations and provide all the correct information for the Thai Revenue Department. We provide a one-stop service to help with the entire administrative process.

Our administrative services include:

Billing (invoices/tax invoices)

Collection (receipts/tax invoices)

Payment (Internet banking process, withholding tax certificate issuance, sending emails for payment references and exchange of receipts/tax invoices)

Bank balance statement updates

Monitoring outstanding invoices

Monitoring collection reports and follow-up collection

Optimum has significant experience in providing our clients with the required documentation for all billing and collection matters. We ensure that all invoices, tax invoices and receipts are professionally and correctly completed to guarantee that your company will not come under any scrutiny by the Thai Revenue Department, which is often the case with incorrectly completed billing. Our service will save you from the hassle of completing documents that can be confusing and also time consuming, which translates into lower costs for you.


At Optimum, our motto is “International expertise for a local price”. If you are looking for international-caliber consulting services from experts with strong backgrounds in tax and accounting in Thailand, we are here to help you. Our team has international experience, including a team member who worked in an international accounting and reporting team for more than 15 years, meaning that we can deliver the capability you require. Our team takes pride in their ability to help companies and individuals comply with Thai tax requirements and local Thai GAAPs to the highest standards. Not only does this provide your business with a significant advantage, but it gives us a sense of achievement to know we have resolved your problems.

International Proficiency Service

with Local Price

For any questions, queries or advice about our tax
and accounting services,
please do not hesitate to contact us.

Optimum Accounting Services Co., Ltd.

Phone: +662 636 3464

Fax: +662 636 3466


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