Quick answer: A 120-hour TEFL certificate may be enough for an employer that accepts that exact course, but the number by itself does not guarantee a job, establish course quality, or give you legal permission to teach or work in Thailand. Compare what the hours include, how much supervised teaching practice you get, and what your target school requires. A 150-hour label is not automatically better; a well-designed course with observed practice and useful feedback may prepare you better than a longer course made mostly of self-study.
Thailand's official teacher-permission, visa and work-permit processes are separate from a TEFL certificate. The official sources reviewed do not establish a universal 120-hour TEFL requirement for all teachers or schools in Thailand. Your school and the relevant authorities decide what applies to your specific role and circumstances.
If you are asking whether TEFL training is necessary at all, see Do You Need a TEFL Certificate to Teach in Thailand?. This guide answers the narrower follow-up: what does “120 hours” actually tell you, and when is it worth choosing more?
What does a “120-hour TEFL certificate” mean?
The number is the course provider's stated estimate or total for a defined kind of learning. It may combine tutor-led contact, guided learning, observed practice, assignments and independent study. Providers do not always count or label those components in the same way.
Before comparing totals, ask each provider to break down its hours:
- How many are live lessons or tutor contact?
- How many are guided learning, assignments or independent study?
- How much teaching practice will I personally deliver?
- Is that practice assessed, observed and followed by feedback?
- What is the exact certificate or qualification title and awarding body?
For example, Cambridge English describes CELTA as at least 120 hours of tutor contact with six hours of assessed teaching practice per candidate, supervised planning, feedback and written assignments, plus 80 additional learning hours. Those details belong to the CELTA specification; they do not make every certificate labelled “120-hour TEFL” equivalent to CELTA.
120 vs 150 vs 168 hours: what changes?
| Course label | What the total can tell you | What it cannot tell you | What to verify |
|---|---|---|---|
| 120 hours | A stated scope that many course pages and job ads use as a comparison point | That every employer accepts it, or that the course includes real, assessed practice | Contact/guided/self-study breakdown; syllabus; practice; assessment; exact award |
| 150 hours | A provider claims 30 more hours than a 120-hour route | Whether the extra hours add depth, relevant specialization or merely more independent tasks | Which modules account for the extra 30 hours; whether they are guided, assessed and relevant to your target role |
| 168 hours | A distinct course may specify 168 guided learning hours and a separate qualification | That 168 is automatically superior, or that it matches a 150-hour course in content or assessment | Qualification register/award details, definition of guided learning, extra assignments, observed practice and employer acceptance |
There is no reliable conversion from the headline number to teaching readiness. Compare the syllabus and assessed practice, not just the total. If a course offers extra hours in young learners, business English or online teaching, consider whether that focus matches the jobs you want. More study is useful when it develops a skill you need and includes meaningful feedback.
Essential TEFL’s official page describes a 120-hour in-person Bangkok course and a separate 168 guided-learning-hour TQUK Level 5 course. The provider says its 120-hour course includes classroom observation and observed teaching practice with real students; it does not publish a specific number of assessed practice hours on the course page. These are provider statements, not an independent audit. Ask for the exact intake schedule and certificate wording before booking. (See the Essential TEFL review.)
Is 120 hours a legal requirement in Thailand?
The official Thai sources reviewed describe teacher authorization, immigration status and work permits. They do not set a single 120-hour TEFL certificate threshold for all teaching jobs.
The Teachers’ Council of Thailand (Khurusapha/KSP) is responsible for professional teacher licensing and relevant temporary permissions. Government guidance describes case-specific permission requested by an educational institution and qualifying education routes. The Ministry of Foreign Affairs lists documents for a Non-Immigrant B teaching visa, and the Department of Employment requires a work permit and related professional documents. A TEFL certificate is training evidence; it is not itself:
- a Khurusapha professional teacher licence or temporary teaching permission;
- a visa or permission to stay in Thailand; or
- a work permit authorizing employment.
Ask the hiring school which teacher-permission path and documents apply to your particular job. Confirm visa steps with the Thai embassy or consulate handling your case and work authorization with the relevant authorities. Requirements can change, and a course provider cannot decide them for you.
What matters more than the difference between 120 and 150?
1. Assessed teaching practice
Ask whether you will teach real English learners, how many lessons you personally deliver, who observes you, how assessment works, and whether you receive specific feedback. “Practicum included” can mean different things. Observing a class is valuable but is not the same as teaching a class yourself.
2. A useful curriculum
Look for lesson planning, language awareness, classroom management, teaching the four skills, adapting for learner age and level, and assessment. Ask for the syllabus rather than relying on a badge or a broad marketing description.
3. Instructor access and feedback
Find out who teaches and assesses the course, how much individual support is available, how quickly work is marked, and what happens if you need to improve an assignment or lesson.
4. Clear hours and assessment
The provider should explain how it counts the total, what must be completed to pass, and how the certificate can be verified. If “120 hours” mostly means independent reading while another course includes sustained tutor support and observed lessons, those totals are not equivalent preparation.
5. Employer confirmation
Schools can set their own hiring criteria. Before paying a deposit, email at least one or two employers or recruiters you genuinely plan to approach. Name the course and qualification, and ask whether they accept it for the role you want. Get the answer in writing.
Does online vs in-person change the answer?
Not by itself. Online courses can offer structured teaching practice and trainer observation; in-person courses can also vary in how much practice each trainee gets. Compare the learning and feedback design, not the screen or classroom label alone.
For online training, ask whether you teach live learners or only submit written assignments, how sessions are observed, and whether the certificate records the format. For an in-person course, ask whether practice involves real learners, how many trainees share the teaching slots, and what happens if a school visit is cancelled.
If format is your main decision, read our online vs in-person TEFL comparison for Thailand. That page covers delivery trade-offs; this article focuses on hour totals and the evidence behind them.
When might 120 hours not be enough for you?
Consider a longer or more specialized course if:
- a target employer explicitly requires a qualification with more hours or a named award;
- you have no teaching experience and want additional supervised practice, not simply a larger number;
- your target role involves young learners, exam preparation, business English or another area that your basic course barely covers;
- you want a qualification with a defined external assessment or regulated-award framework, and you have verified that exact award;
- you need more time with a trainer to build confidence in lesson planning, language explanations or classroom management.
If the school accepts 120 hours and you already have relevant experience, a 150-hour course may add little value unless its extra modules address a real gap. If you do need more preparation, compare a clearly assessed practicum or a recognized, well-specified qualification rather than buying a course solely for the larger hour count.
Questions to ask a school before you choose
Send a short message with your target role and exact course details. Ask:
- Do you require TEFL/TESOL/CELTA for this position, or is it optional?
- Is there a minimum number of course hours? How do you count online, guided and independent learning?
- Do you require observed teaching practice? If yes, how many hours and what kind of learners?
- Will you accept [exact course title, provider and awarding body] for this role?
- Are a degree, nationality, English level, experience or other documents separate requirements?
- What teacher-permission, visa and work-permit process applies, and who submits each application?
Do not treat “120 hours is fine” as confirmation of hiring or legal eligibility unless the school answers the exact certificate and role question. Hiring needs can change before you apply.
A quick decision checklist
A 120-hour route may fit if you can check all of these:
- My target school accepts this exact certificate or does not require a higher-hour award.
- I can see a syllabus and understand what the 120 hours include.
- I know whether I will teach real learners and how my practice is assessed.
- I will receive feedback from a qualified trainer and understand the assessment rules.
- The exact certificate title, issuer and verification process are clear.
- I have separately checked my degree, teacher-permission, visa and work-permit path with the employer and relevant authorities.
If one or more boxes remain blank, get answers before paying. The right choice may be a stronger 120-hour course, a 150/168-hour course with relevant depth, or a different qualification altogether.
What Essential TEFL says its Thailand courses include
Essential TEFL's current official course pages describe a four-week, in-person 120-hour course in Bangkok with classroom observations, teaching practice with real students in Thai schools, trainer observation and feedback. Its dates-and-fees page also lists a separate TQUK Level 5 option with 168 guided learning hours, extra assignments and portfolio work. The provider page does not give the 120-hour route's exact number of observed or assessed teaching-practice hours, so request the timetable for your intake.
These course details are attributed to Essential TEFL and have not been independently audited by SiamTEFL. Confirm current price, certificate wording, practice hours, assessment, refund terms and eligibility directly with the provider. An online description of a course is not a guarantee of employment or work authorization.
If you are comparing this provider with other options, see our Essential TEFL review and the broader TEFL course selection guide.
The short answer
120 hours can be enough when the course is well designed and your target employer accepts the exact award. The number alone cannot prove either point. For the most useful comparison, ask for the hour breakdown, syllabus, assessed practice, feedback and written employer acceptance. Choose 150 or 168 hours when the additional training fills a real need or meets a stated requirement.
Essential TEFL is one option to investigate. Check its current details and compare them with your needs using the official course information and our independent review. This article contains the referral URL Essential TEFL course details. If you enrol through it, SiamTEFL may earn a commission at no extra cost to you. The referral does not affect the assessment. Read our affiliate disclosure.
Course offerings and official requirements can change. Verify the exact course, target employer's criteria and current Thai authorization process for your case before booking or accepting work.
For primary-source context, see the Teachers’ Council temporary teaching-permit criteria, the government’s foreign-teacher licensing guidance, the Ministry of Foreign Affairs Non-Immigrant B guidance, and the Department of Employment teacher work-permit notice. These processes are distinct from a course certificate; confirm the current route for your case with your school and the relevant authority.