Employment Contract Types in Thailand: Fixed-Term, Permanent, and Project-Based — What HR Must Know

Picture this: you hired someone on a “temporary” basis six months ago, and now they’re claiming severance pay as if they were a full-time permanent employee. Sounds familiar? This scenario plays out more often than it should in Thai workplaces — and it almost always traces back to one root cause: the wrong employment contract type was used, or the contract wasn’t drafted clearly enough.

Whether you’re an HR Manager at a growing Thai SME or an HR Director at a multinational with Thailand operations, understanding the distinctions between the main employment contract types in Thailand is non-negotiable. Thai labor law is clear on what each contract entails — and the consequences of getting it wrong can range from unexpected compensation claims to full-blown labor court disputes.

Let’s break it down.

Under Thailand’s Labour Protection Act B.E. 2541 (1998) and its amendments, the type of employment contract you use determines:

• Whether the employee is entitled to severance pay upon termination
• What notice period applies when ending the employment relationship
• The employee’s leave entitlements and other statutory benefits
• How the relationship is interpreted by labor courts in the event of a dispute

Getting the contract type right from day one isn’t just good HR practice — it’s essential risk management.

1. Permanent (Indefinite-Term) Employment Contract

The most common type in Thailand, a permanent contract has no defined end date. Once an employee passes their probation period (typically capped at 119 days in practice), they become a confirmed permanent employee with full statutory rights.

Key features:

• No fixed end date
• Employee entitled to full statutory benefits: annual leave, sick leave, severance pay, etc.
• Termination requires advance notice OR payment in lieu of notice
• Severance pay is mandatory upon termination without cause, calculated based on length of service under Section 118 of the Labour Protection Act
• Ranges from 30 days’ pay (for 1–3 years of service) up to 400 days’ pay (for 20+ years)

Best for: Core business functions requiring continuity — accounting, HR, sales, operations, engineering, and so on.

Important note: Even if no written contract exists, an open-ended working relationship is typically treated by Thai courts as an indefinite-term contract. Always document.

2. Fixed-Term Employment Contract

A fixed-term contract has a clearly defined start and end date. Under Thai law (Section 17/1 of the Labour Protection Act), this contract type is only legally valid for specific categories of work:

• Project-specific work that falls outside the employer’s core business activities
• Seasonal work tied to a specific season or peak period
• Occasional work with a defined completion date

Duration: Fixed-term contracts must not exceed 2 years and must be established in writing from the outset.

The most common HR mistake here: Renewing fixed-term contracts multiple times with the same employee in the same role. Thai labor courts have consistently interpreted repeated renewals as evidence of a de facto permanent employment relationship — triggering severance obligations the employer never planned for.

Best for: Maternity/sick leave cover, specialist consultants brought in for a defined scope, seasonal hospitality or retail staff.

3. Project-Based Employment Contract

Project-based contracts are a subset of fixed-term contracts under Thai law, but with the end date tied to project completion rather than a calendar date. The same legal conditions apply — the work must be outside the employer’s core business, and the contract must be in writing.

Best for:

• IT development projects (ERP implementation, system upgrades)
• Construction or engineering scopes
• Short-term consulting engagements
• Event production or marketing campaign execution

What your contract must specify:

• A clearly defined scope of work
• Measurable deliverables
• Termination conditions (project completion or a long-stop date)
• Compensation structure (monthly, daily, or milestone-based)

❌ No Written Contract

Thai law doesn’t always require a written contract, but the absence of one is the single biggest legal risk for employers. If a dispute reaches the labor court, the burden falls on you to prove the agreed terms.

❌ Renewing Fixed-Term Contracts Without Justification

Repeatedly renewing a fixed-term contract in the same role is the fastest route to an unplanned severance liability. Each renewal should be justified by a genuine, documented business reason.

❌ Contract Clauses That Contradict Thai Law

Any clause that gives employees fewer rights than Thai labor law guarantees is automatically void. For example: a clause stating an employee waives their right to severance pay is unenforceable.

❌ Outdated Contract Templates

Thai labor law has been amended several times in recent years, including changes to parental leave, severance calculation, and overtime rules. If your contract template hasn’t been reviewed since 2020, it probably needs an update.

1. State the contract type clearly at the top Don’t make the reader guess. Specify whether this is a permanent, fixed-term, or project-based engagement — and if fixed-term, state the end date and the reason for the fixed term.
2. Document the reason for a fixed-term arrangement Something as simple as “to cover [Employee Name] during maternity leave from [date] to [date]” or “for the implementation of [Project Name]” provides valuable legal context and reduces the risk of the contract being reclassified.
3. Specify the probation period and its conditions For permanent contracts, include a probation clause of up to 119 days with clear performance expectations and termination conditions during probation.
4. Use a digital document management system A tool like Sprout Keeper keeps every employment contract organized, searchable, and secure — with role-based access and PDPA-compliant storage. No more hunting through filing cabinets when a dispute arises.
5. Make sure your payroll system handles all contract types Severance calculations, leave entitlements, and statutory contributions vary by contract type. Sprout’s Payroll Application is designed for the Thai market and handles all three contract types accurately — reducing compliance risk and manual calculation errors.

Managing the full HR lifecycle across multiple employment contract types in Thailand is genuinely complex. Sprout is built specifically for the Thai HR context, giving your team the tools to handle it end-to-end:

• Sprout Keeper — Digital employee document vault. Store, access, and manage employment contracts with PDPA-compliant security.
• Payroll Application — Automated payroll with accurate severance, tax, and social security calculations for all contract types.
• Leave Application — Manage leave entitlements correctly for permanent, fixed-term, and project-based employees alike.
• Attendance Application — GPS and facial check-in, OT tracking, and shift management — for your entire workforce, regardless of contract type.

Want to see how Sprout fits your organization? Book a free demo with our team today — no commitment, just a 30-minute conversation.

What are the main employment contract types in Thailand?

There are three primary types: Permanent (Indefinite-Term), Fixed-Term, and Project-Based. Each carries different obligations for the employer under Thailand’s Labour Protection Act, particularly around severance pay and termination conditions. Understanding the difference is fundamental for any HR professional operating in Thailand.

Are fixed-term employees in Thailand entitled to severance pay?

If the fixed-term contract is legally valid (covering project-specific or seasonal work) and expires naturally at its agreed end date, no severance pay is typically required. However, if the employee is dismissed before the end date, or if the contract has been renewed enough times to be reclassified as permanent, severance obligations apply under Section 118 of the Labour Protection Act.

How many times can you renew a fixed-term contract in Thailand before it becomes permanent?

Thai law doesn’t set a specific number of renewals. However, Thai labor courts look at the totality of the relationship — including the nature of the work, the frequency of renewals, and whether the work is truly outside the core business. HR should review and document the justification before every renewal.

What is the probation period for permanent employees in Thailand?

Thai law doesn’t specify a maximum probation duration, but the practical standard is 119 days (just under four months). This is because employees who have worked for 120 days or more become entitled to severance pay under Thai law, so probation periods are commonly capped to preserve termination flexibility before that threshold.

What’s the difference between a Project-Based and a Fixed-Term contract?

Legally, they fall in the same category under Thai law. The practical difference is what triggers the end of the contract: a fixed-term contract ends on a specified calendar date, while a project-based contract ends upon completion of the defined scope. In practice, HR teams often include both a target completion date and a project-completion trigger in project-based contracts.

Do employment contracts need to be in writing under Thai law?

Thai law doesn’t require all employment contracts to be written, but the absence of a written contract is a significant legal risk for employers. In any labor dispute, the employer bears the burden of proving agreed terms — and without documentation, this becomes extremely difficult. Always put it in writing.

How does a freelancer or contractor differ from a fixed-term employee in Thailand?

Freelancers and contractors operate under civil law as independent service providers, not as employees under the Labour Protection Act. This means no statutory severance, no annual leave entitlement, and no social security contributions. However, if the working arrangement resembles employment in practice (set hours, supervision, exclusivity), Thai courts may reclassify it as an employment relationship — creating retroactive liabilities for the employer.

The distinctions between employment contract types in Thailand are not merely administrative — they have real financial and legal consequences. A well-drafted contract protects both the employer and the employee, sets clear expectations, and dramatically reduces the risk of disputes down the road.

If your organization is still managing contracts on paper or in disconnected spreadsheets, it’s time to upgrade. Sprout Keeper and Sprout’s Payroll Application are designed to make this easier — so your HR team can focus on people, not paperwork.

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