What should a Website and Software Development Agreement include under Thai law?

1. Definitions and Interpretation
2. Engagement and Standard of Work
3. Project Management
4. Client's Responsibilities
5. Changes
6. Timetable and Delay
7. Acceptance Testing
8. Price and Payment
9. Taxes
10. Production Accounts and Access
11. Source Code and Delivery Materials
12. Intellectual Property
13. Use of AI Tools
14. Warranty and Defect Correction
15. Confidentiality
16. Personal Data and Security
17. Personnel and Independent Contractor
18. Liability and Indemnities
19. Force Majeure
20. Termination
21. Notices
22. Governing Law and Disputes
23. General

• A contract to build software for a price is a hire of work (Instrument 4 of the Stamp Duty Schedule). Duty is 1 THB for every 1,000 THB or part of 1,000 THB of the price. On the Contract Price you entered, the duty on the original is the amount the system calculates from the figures entered, and each counterpart carries the amount the system calculates from the figures entered.Because the price is in …, convert the Contract Price to Thai Baht at the exchange rate on the date of signing and calculate the duty on the Baht amount. Each counterpart carries 5 THB, or 1 THB if the duty on the original is 5 THB or less.
• By law the Developer pays and cancels the stamp duty (Clause 9.3 confirms this). A Change Order that increases the price needs additional duty.
• If the price is 1,000,000 THB or more, the duty must be paid in money to the Revenue Department instead of by affixing stamps. If the Agreement is signed electronically, pay through the Revenue Department's e-Stamp Duty system before signing or within 15 days after signing.
• An unstamped agreement cannot be used as evidence in a Thai civil court until the duty and a surcharge of up to six times the duty are paid (Revenue Code section 118). The Developer needs a stamped agreement to sue for unpaid instalments.

• A Developer registered for VAT in Thailand charges VAT on each instalment and issues a tax invoice (Clause 9.1). Check that the VAT option you chose matches the quotation.
• A Thai company that pays a Thai Developer for this work normally withholds 3% and gives a withholding tax certificate (Clause 9.2).
• If the Developer is abroad, the Thai Client may have to withhold a different rate of income tax, and may also have to pay VAT to the Revenue Department on the Developer's behalf for work used in Thailand. A double tax treaty may reduce the withholding. Ask an accountant before the first payment, especially because you ticked gross-up, so the Client bears the withholding tax on top of the price.

• The Client owns the software from payment of each instalment (Clause 12.2). A transfer of copyright is valid only if it is in writing and signed by the transferor and the transferee (Copyright Act section 17), so both Parties must sign this Agreement, and every person who wrote code for the Developer must have signed a written agreement with the Developer (Clause 12.4). Code written by an employee belongs to the employee unless they agreed otherwise in writing (section 9).- The Developer keeps the copyright and the Client receives a permanent licence to use and modify the software, including its source code (Clause 12.2). The Client may not sell the software to others as a product. If you later want to own the software outright, sign a separate written assignment of copyright.
• Insist on the source code and the other Delivery Materials with each paid Milestone (Clause 11). A system that works but has no source code cannot be maintained by anyone else.
• Before final acceptance, ask a second developer to try to build and deploy the software from the Delivery Materials alone. If they cannot, the Delivery Materials are not complete.
• Check the list of open-source components (Clause 12.5). Some licences require you to publish your own source code if you distribute the software.

• Register the domain, hosting, cloud, app store and repository accounts in the Client's own name and keep the owner password and recovery email yourself (Clause 10.1). Give the Developer a separate user with only the access it needs.
• When the Work ends, remove the Developer's access and change shared passwords, unless you sign a maintenance agreement. Accessing a computer system after the right of access has ended may be a criminal offence in Thailand.
• The Developer may not lock the system or add a "kill switch" to force payment (Clause 10.3). Its remedies for late payment are interest, suspension of further work and termination.

• Test each delivery within … Business Days and list every Defect in writing with steps to reproduce it, or the delivery is treated as accepted (Clause 7.6). Launching the software counts as acceptance.
• If the software is late and you still want liquidated damages, say in writing on the day you accept it that you reserve the right (Clause 6.4). A Thai court may refuse the claim if you accept without reserving it, and may reduce damages that are excessive.
• Report Defects found after launch within the Warranty Period of … days (Clause 14). For updates, new features and hosting care after that, sign a separate maintenance and support agreement.

• When the Developer can see real customer or employee data, it is your data processor (Clause 16.4). The Personal Data Protection Act requires a processor to act only on your instructions, keep the data secure and report breaches (section 40). You, as controller, must usually notify the Personal Data Protection Committee within 72 hours after becoming aware of a breach (section 37), which is why the Developer must tell you within 48 hours.
• Storing or accessing the data outside the place you entered (…) needs your written consent and must meet the Act's rules on transfers abroad (sections 28 and 29).

• A company should sign through the director or directors authorised in its latest company affidavit, and affix the company seal if the affidavit requires one. For a foreign company, ask for a recent certificate of incorporation and evidence of the signatory's authority.
• Clause 23.7 allows electronic signatures and signed PDF copies. Keep the final signed file unchanged, together with Schedules 1 and 2 and every Change Order.
• Keep the release notes, test results, Defect notices, Acceptance Certificates, invoices and transfer slips for every Milestone. They decide most software disputes.

• A Thai court works in Thai. A Party that relies on this Agreement, or on English emails and documents, must file a Thai translation certified as accurate. Budget for this cost.
• If the other Party has no assets in Thailand, a Thai judgment may be hard to enforce abroad. An advance payment and milestone payments protect a Developer better than a court case; holding back payment until each Milestone passes testing protects a Client. An arbitral award is easier to enforce in other countries.

Compiled from the notes that accompany the English contract templates on this site, published by Phuwara Krobtaku (ภูวรา ครอบตะคุ), Thai attorney-at-law, licence no. 477/2558. The short answer and summary at the top of this page are put together by the site from the template's clause headings and notes. Statutes are quoted only in the official Thai text: Thai is the only official language of Thai legislation, and an unofficial translation can mislead. Article registry OKC-16142A. If you reuse this content, please credit the author and link to the original.