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What is TESOL Certification? [Full Guide 2024]

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Teaching English to Speakers of Other Languages

When people think about a career in Teaching English to Speakers of Other Languages (TESOL), they imagine taking off a year or two to relax on sunny beaches, find inspiration in ancient ruins, learn a new language, or get lost in an exciting location abroad.

While that’s not so far from the truth, there is more to TESOL than teaching English abroad during your gap year. There are plenty of lucrative jobs in over 30 countries and plenty of career advancement opportunities to choose from.

What is the Difference Between TESOL, TEFL, and TESL?

…the TESOL/TEFL/TESL acronym is often a matter of personal choice on the part of the institution offering the certification… the source of the certification is far more important than the acronym used on the certificate.

What is TESOL exactly? TESOL stands for Teaching English to Speakers of Other Languages. TESOL, TEFL, and TESL are acronyms that refer to the same industry. English language teaching can be a very rewarding profession, but admittedly the terminology surrounding it isn’t very consistent. 

If you started your journey for English teaching certification by doing research, you likely encountered a wide and puzzling variety of acronyms:

  • TESOL: Teaching English to Speakers of Other Languages
  • TEFL: Teaching English as a Foreign Language
  • TESL: Teaching English as a Second Language. In Canada, accrediting and professional groups carry the TESL designation (i.e. TESL Canada, TESL Ontario, ATESL, and TESL Toronto).

These designations are most widely used to describe a professional certification in the field of English language teaching. For the most part, there is no substantial difference among them: the TESOL/TEFL/TESL acronym is often a matter of personal choice on the part of the institution offering the certification. The methodology of TESOL, TEFL, and TESL is the same. Whether you want to teach English abroad or teach in an English immersion program in North America, the Communicative Language Teaching (CLT) method prevails all over the world. So, what matters most when choosing a TESOL, TEFL, or TESL course is that you learn to use the major ESL lesson planning frameworks that you need to teach different levels of ESL students and that the course is fully recognized for teaching positions anywhere you want to go.

Should a prospective employer require certification, the source of the certification is far more important than the acronym used on the certificate. A TESOL/TEFL/TESL certificate from a teacher training organization that is institutionally accredited and their courses are externally recognized by an industry-leading accrediting body will yield the best responses from employers.

OnTESOL is institutionally accredited by ACCET (U.S. Department of Education recognized agency) and offers online TESOL and TEFL courses recognized by TESL Canada and TESL Ontario. The OnTESOL certificate is valid for teaching jobs worldwide so you never have to take another TESOL/TEFL/TESL course again. Use your OnTESOL certificate to teach English in Canada or the United States, obtain the work visa to teach English in a foreign destination, or qualify to teach English online

Read more: Compare TESOL certification courses by career path and teaching destination

Types of TESOL Courses and Certification Standards

While there is no single international TESOL accrediting body, the leading accreditations in Post-Secondary Education and TESOL training are ACCET (U.S. Department of Education Recognized Agency), TESL CanadaTESL Ontario, Trinity College London, and the University of Cambridge (CELTA). Of course, there are dozens of other TESOL accrediting bodies, but the majority were established by TESOL course providers looking to accredit themselves.  

A 120-hour course recognized by a leading TESOL accrediting body provides a great foundation in grammar, phonology, and methodology, as well as an in-class teaching practice module with real ESL students. You can also take a 250-hour, 500-hour, or even a Master’s degree program through a recognized course provider.

The Leading Post Secondary Education and TESOL Training Accreditations from Around the World

Here you can get to know some of the most widely recognized accrediting bodies in the world that offer Post Secondary Education and TESOL accreditation:

Accrediting BodyDescription
TESL CanadaA Canadian accrediting body that validates on-site and online/distance learning programs all over Canada at three levels: Professional Standard Level 1, Level 2 and Level 3.
TESL OntarioTeachers of English as a Second Language Association of Ontario, which validates on-site and online/distance learning programs in Ontario at two levels: Adult ESL Teacher Accreditation CTESOL and Adult ESL Teacher Accreditation OCELT.
Trinity College London, UKA British accrediting body, which validates on-site and blended programs all over the world at two levels: Trinity CertTESOL and DipTESOL.
Cambridge Assessment English, UKA British accrediting body, which validates on-site and online CELTA certificate, and DELTA (Diploma Level)
ACCETUS-based Accrediting Council for Continuing Education & Training (ACCET)

TESL Canada, TESL Ontario, Trinity College London, and CELTA are the leading external TESOL-related organizations in the world. They are renowned for setting the minimum TEFL / TESL / TESOL certification standard at 120 hours of training, including a Practicum that ranges between 6 and 20 hours. A TESOL course recognized by one of these organizations provides a great foundation in all the areas of grammar, phonology, and methodology that an English language teacher needs to master for a successful career in TESOL.  

These external TESOL accrediting bodies do not offer their own courses. Their job is to recognize TESOL courses from universities and private institutes, ensuring that they meet accreditation standards through some combination of auditing course materials, trainers’ qualifications, and course delivery. As an external accreditation body, they help the industry to standardize training and offer external certification to graduates of recognized TESOL courses.  

While the leading organizations from Canada and the UK set the minimum international TESOL standard at 120 hours, they also accredit professional development courses under 500 hours and Master’s degree programs in TESOL.  Last but not least, some of them support the development of the international TESOL industry through conferences, research, and publications. 

ACCET is the leading accrediting body for non-traditional post-secondary educational providers from the United States and internationally. ACCET accredits Post-Secondary institutions from a wide variety of sectors, including TESOL certificate course providers. Accredited ACCET institutes must meet 9 standards related to organizational management, policies, and processes.

Although ACCET standards are not specific to TESOL, this US-based accreditation body has a positive impact on the quality of TESOL training. For example, accredited institutions must have processes in place to teach practical skills through Lab Assignments, offer standardized training through a rubric-based mode of assessment, and include live synchronous options. Therefore, a TESOL certification from an accredited ACCET institute shows employers that the candidate completed a quality teacher training course with a reputable organization. 

What’s the difference between UK, Canada, and U.S. TESOL certification courses?

Quality TESOL courses offer advanced training in grammar, phonology, and methodology. It makes absolutely no difference where the program comes from as long as it’s a quality program.  

In grammar and phonology, the trainee learns the rules of the language. These rules are standard, meaning that they are not specific to any native-speaking country.

Methodology is the most important part of a TESOL or TEFL course. The methods for teaching English are standard across the world and the quality of the course depends on the course material, assignments, and the teacher trainer. Methodology is where trainees learn how to use different ESL teaching methods in their lesson plans, so a quality TESOL course should include advanced lesson planning Lab Assignments that teach trainees how to use a variety of ESL lesson planning frameworks according to the topic of the class and the level of students they are teaching. 

For over 30 years, external TESOL-specific accrediting organizations such as TESL Canada, Trinity CertTESOL (UK), and CELTA (UK) have set the highest standards of the ESL teacher training industry.  A TESOL course recognized by one of the 3 leading accreditations is considered academically equivalent to a course recognized by another leading organization. 

A TESOL course that is not recognized by one of the leading accrediting bodies from Canada or the UK is generally considered sub-par because they cut corners to make it easy to pass with multiple choice tests and short essays. These sub-par TESOL / TEFL courses may teach knowledge about TESOL methodology but they fail to teach valuable skills such as lesson planning.

While the United States doesn’t have a TESOL-specific accrediting organization, TESOL certification courses from leading UK and Canadian providers are available both in-class and online in the United States and around the world. Furthermore, the United States has unique government-recognized and internationally-renowned accrediting bodies such ACCET, which focuses on institutional accreditation of post-secondary education.  A TESOL institute accredited by ACCET must meet a wide range of organizational standards to ensure they offer quality training at the highest standards of their industry. OnTESOL is the only online TESOL / TEFL course provider accredited by ACCET and recognized by TESL Canada. 

How to Start Your Career

You have several options to jumpstart your ESL teacher career. Once you’ve gotten your certificate, you’ll be able to apply for teaching jobs in a variety of areas, as defined below.

Teaching English Immersion in Native Speaking Countries

Canada, the United States, and the United Kingdom have the largest TESOL markets in the world, offering ESL immersion programs to millions of students who want to study English abroad, take their TOEFL or IELTS test, or get ready for university.

The TESOL industry in native-speaking countries is quite large and lucrative. Some language schools incur annual revenue upwards of $30 million with just one location. As you can imagine, there are plenty of career advancement opportunities in this lucrative industry.

The great thing about pursuing a TESOL career is that, unlike a public-school teacher career, a Bachelor degree in Education and teaching experience are not required to teach ESL immersion classes at private institutes in Canada, the USA, or the UK. Apart from the citizenship/permanent residency job requirement, a university degree in any area and a recognized TESOL certification are sufficient to start a career in TESOL.   


In Canada, the minimum job requirement is TESL Canada Standard 1 certification

In the United Kingdom, the minimum job minimum requirement is CELTA, Trinity CertTESOL, or equivalent 120-hour TESOL certification with a minimum Practicum of 6 hours. 

In the United States, the minimum job requirement is a university degree and a 120-hour TESOL/TEFL certificate from a reputable provider. While there isn’t a specific certification requirement to teach English immersion in the United States, a TESOL certification from an ACCET accredited provider shows US employers that the candidate completed a quality TESOL training course with assessment and processes in place to teach trainees the practical skills they need to succeed on the job. 

Teaching English Abroad

Teaching English abroad is another great way to start your TESOL career. ESL teachers in immersion programs encounter students from all over the world. Those with experience teaching English abroad are better able to understand their students’ language and cultural challenges. 

Starting your TESOL career abroad will give you a deeper understanding of the methodologies employed in the ESL classroom and help you advance your career in numerous ways. For example, when you go abroad you will encounter the same experiences that your ESL students experience when they take an English immersion program in your home country. Experiencing culture shock will give you a sense of compassion that you can only get by living in another country for an extended period of time. 

Learning a new language by living abroad will give you great insights into new language acquisition and the methodology of Teaching English to Speakers of Other Languages (TESOL). For these reasons, we recommend teaching English in at least two foreign countries with different languages to make the most of your TESOL career.


In general, the minimum requirement to teach English abroad is a university degree in any area and an ESL teacher certificate of at least 120 hours. Many schools abroad have a native speaker requirement due to work visa regulations.

Since there isn’t a single international TESOL accreditation, some language programs accept any TESOL / TEFL certification while others require a TESOL / TEFL certification from an accredited provider due to work visa regulations.  Starting your career with the right training is highly recommended so you don’t have to take your teacher training course again with an accredited organization when you want to continue teaching English in another country.  

Teaching English Online

Nowadays, you can start your TESOL career as an online ESL teacher.  Teaching English online is an excellent way to earn a full-time income or simply some extra money in your spare time – all from the comfort of your home.

Teaching English online is a popular option for both English native speakers and non-native speakers. Unlike teaching English abroad, you will have greater flexibility to set your own schedule, work as much or as little as you want and work from anywhere with good internet. 

The option to teach English online is also ideal for ESL educators who would like a flexible side gig. For example, it’s the perfect job for stay-at-home parents who need stable income, new TESOL graduates who want to gain teaching experience before going abroad, or expats who need a good-paying job while traveling abroad. By teaching English online, you can get a steady stream of income, make your own schedule and work on your own terms. 

Career Advancement Opportunities for ESL Teachers

Every teaching journey is unique. Becoming an English language teacher can be a gateway into other teaching and career advancement opportunities. In fact, many ESL teachers transition into other career paths related to the field. Some continue their career in Education as licensed public-school teachers in Canada or the United States by pursuing their Master of Education. Many others continue their career in management, training, and administrative roles specifically related to the TESOL industry.

1. Highly Paid Teaching Jobs for Experienced ESL Teachers

The first step to progress in your TESOL career is to specialize as an ESL teacher and apply for lucrative IELTS and Business English teaching jobs. These adult ESL teaching positions specialize in English lessons for educational and professional purposes. They are the best next step in your TESOL career because the requirements do not change much from regular ESL teaching positions. A university degree in any area and a recognized TESOL certification are the main requirements. However, a minimum of 3 years of ESL teaching experience is required by top schools offering IELTS exam preparation and Business English courses..

2. Teacher trainer or headteacher of a language school

Once you get solid experience, you may qualify to become a teacher trainer or headteacher at your school. This means training and managing other teachers, preparing curriculum materials and handling scheduling and staff problems. A headteacher typically earns a much higher salary. For these positions, a Master degree in TESOL or Education is generally the minimum requirement.

3. ESL administrative support role

Language school don’t just need teachers – they also need support staff. This includes employees working in human resources, marketing and logistics. Understanding the inner-workings of the school can help you transition to one of these administrative roles.

4. ESL managerial role

All schools need great principals and directors. These managerial roles are well-paid and involve great responsibility for the seamless running of the school and staff. Director of Studies roles are common abroad and in English language schools within native-speaking countries. A Master’s degree in TESOL is generally required for DoS positions. 

5. University or college lecturer

TESOL teachers may also get the opportunity to lecture or teach at the university level. This is especially true after establishing a proven record of teaching and publishing articles about education. Depending on location, a Masters degree in TESOL may be required.

6. Educational author or speaker

Educational thinkers are another popular job prospect. Teachers who write books, speak at conferences or otherwise share insights on education can get income in this way.  

7. Private freelance tutor

You can also start your solo career as a freelance tutor. This individualized method can also earn you more, as one-on-one sessions cost more.

8. Curriculum designer 

If your skills lie in making great lesson plans, you might consider designing curriculums. Often language schools will pay for great curriculum content, especially if it’s specialized. 

9. Teacherpreneur

Finally, you may become a teacherpreneur and start your own language institute, curriculum website or tutoring service. You can use your strengths and insights to run your own education business.

As you can see, career opportunities for TESOL certified teachers are truly endless. After getting solid experience in the classroom, you may be ready to shift into one of these education-related roles.

What Type of TESOL Certification do I Need to Teach in…?

The TESOL certification level you require will depend in large measure on your own background and the region where you plan to teach English. Demand is very high in fast-growing economies such as Vietnam, South Korea, Taiwan, Malaysia, Thailand and many Latin American countries. 

Generally speaking, the minimum entry-level requirement for English teaching jobs is a 120-hour TESOL, TESL, or TEFL certificate. Some schools prefer to hire teachers who have more than 1 year of teaching experience and/or completed a teaching practice module of 20 hours.

Of course, academic requirements will vary tremendously based on location. The higher-end schools in the more desirable locations can (and will) demand a Bachelor’s degree, TESOL certification and teaching experience. In locations where demand for teachers outstrips supply, there are still some prospects for those with lower qualifications. In this case, certification is a plus but not mandatory, and candidates will be judged on a case-by-case basis. Find teaching jobs on our job board.


  1. Minimum 120 hour TESOL certification.
  2. Teaching practice or experience not necessary for about 90% of entry-level jobs in Asia.
  3. A Bachelor’s degree is required for the work visa. Some places like Japan, Thailand, and Cambodia may accept college diploma or associate degree. Contact the embassy for more information about the requirements for the work visa. Some programs, such as the NETs program in Hong Kong, prefer to hire people who have a BA degree in Education.


  1. Minimum 120 hours. Advanced training with Practicum, such as courses approved by TESL Canada or CELTA, are preferred.
  2. EU citizenship is required for most countries. Germany and the Czech Republic have more flexible immigration options for qualified candidates.

Latin America:

  1. Minimum: 120 hour TESOL certification.
  2. Teaching practice or experience not necessary for about 90% of entry-level jobs in Latin America.
  3. A BA in any area is sufficient for about 90% of entry-level jobs in Latin America. Some countries do not require a university degree to issue the work visa. Check with the embassy if you do not have a degree.

Middle East:

  1. 80% of all jobs in this region are in the public school system. Some countries offer lucrative contracts. These public school jobs require a BA in Education or a Teaching license. Teaching practice or experience not necessary for about 90% of entry-level jobs in the Middle East.
  2. Master’s degree preferred in some competitive jobs. Teaching experience preferred.
  3. TESOL certification is highly recommended for those who teach primary and secondary classes in English to non-native speakers.

North America, UK, Australia, New Zealand, And South Africa:

  1. Minimum 120 hours and a 20-hour Practicum. (TESL Canada or CELTA equivalent). A BA in any area is sufficient for language academy and English immersion jobs. MA degree preferred in some competitive jobs. Teaching experience preferred.
  2. For the public school system, a teaching license or MA degree in Education is required in native-English speaking countries.

Online Worldwide:

  1. Minimum: 120-hour TESOL Certificate
  2. Most established online companies required a BA in any area. There are companies that will accept current university students, while others do not require a degree at all.

In addition to the academic qualifications listed above, a love of teaching is probably the best qualification you can have. A teacher with a strong emotional core, a desire to serve and a personal sense of achievement when students succeed will reach the highest levels of the profession, beyond anything a TESOL training course can provide.

Should I Get My Certificate Online or With an On-Site Course?

In essence, there shouldn’t be any difference in quality between on-site and online TESOL courses. Thanks to current technologies, it is possible to deliver top TESOL/TEFL training online without lowering the quality of the course. 

Today, online training is equally recognized by the leading Post Secondary Education and TESOL accreditations. The UK-based CELTA and Trinity CertTESOL brands recently launched their own online version.  In the United States, ACCET accredits online TESOL institutes such as OnTESOL. Since OnTESOL launched the first online course in 2003, TESL Canada has recognized online TESOL courses offered by the most reputable Canadian universities and private institutes.

The main problem with most online TESOL courses out there is not the delivery model. It is the content of the course and the level of the assignments. For this reason, an advanced program from a recognized TESL Canada, Trinity CertTESOL, or CELTA provider is recommended for a career in TESOL.

Getting Your Teaching Certification Online

The online TESOL certification courses offered by OnTESOL were designed by Coventry House International. We use their Trinity CertTESOL syllabus to offer quality TESOL training in an online format. All our courses are recognized by TESL Canada.

The courses offered by OnTESOL go beyond the theory and methodology of teaching English. All our online TESOL courses are assessed through practical lesson planning assignments that will prepare you to use the Communicative Language Teaching method anywhere in the world.

120-hour Advanced TESOL Certificate: 

Valid for teaching jobs worldwide! Few online TESOL/TEFL schools have experience delivering advanced courses such as Trinity CertTESOL, TESL Canada, or CELTA. Coventry House International-OnTESOL offers 20 years of experience delivering quality TESOL courses online. We have taken elements from our in-class Trinity CertTESOL and TESL Canada courses to compile a standard 120-hour TESOL course that truly teaches trainees how to create professional lesson plans. (View course)

168-hour Hybrid TEFL Certificate:

Our new interactive live option via Zoom! Combine the 120-hour course with the 10-hour Live Lesson Planning Workshop to become an expert on lesson panning frameworks and complete the course faster. This TEFL certification course also includes 3 specialists to prepare you for teaching jobs abroad and online (View course).

250-hour TESOL Diploma: 

This program covers more than any 4-week TESOL course, including CELTA. We’ve taken Coventry’s 5-week Trinity CertTESOL and TESL Canada Standard 1 and included more advanced materials and assignments. This program is recognized by TESL Canada Professional Standard 2 after completing a 50-hour Practicum. TESL Canada Professional Standard 2 is offered by some of the most reputable Canadian universities. Coventry House International-OnTESOL offers a great level of training for an affordable price. (View course)

Frequently Asked Questions:

1. Do I need to be a native English speaker to teach ESL or EFL?

No, absolutely not. Non-native speakers are more than welcome to apply. In fact, a large percentage of our online student-teachers in the various courses we offer are non-native speakers of English from a variety of countries: Saudi Arabia, Egypt, Turkey, Bulgaria, Italy, France, Germany, Switzerland, India, Korea, Japan, China, Taiwan, Vietnam, The Philippines, Malaysia, Argentina, Chile, Brazil, Mexico, and Colombia.

Non-native speakers should possess a strong command of both written and spoken English. Graduates who wish to pursue TESL Canada certification after the online TEFL / TESOL course with OnTESOL, need to meet proficiency requirements.

2. Why are online TESOL courses more affordable?

The price of an expensive on-site course is not indicative of quality. Online TESOL courses can be offered for a much lower tuition fee because the need to rent expensive downtown classrooms is eliminated. Furthermore, online education provides great economies of scale because schools have a global reach.

We are convinced that online instruction is the way of the future. In fact, TESL Canada and CELTA recognize some online TESOL courses.

3. How does OnTESOL compare with CELTA?

Our 120-hour Advanced TESOL Certificate is academically equivalent to CELTA. Our 168-hour and 250-hour TEFL / TESOL courses are more comprehensive than the CELTA certification course.

TESL Canada is the national accrediting body and they accept CELTA and Trinity CertTESOL as equivalent to Standard 1 for those who took CELTA/Trinity abroad and need to get the equivalency to teach in Canada. For international jobs, 120 hours with Practicum (with real ESL students) is considered equivalent to CELTA. 

In terms of course content, our online courses are based on the in-class Trinity CertTESOL which has a stronger focus in lesson planning than CELTA. CELTA trainees do lesson planning as part of the Practicum but the course assignments are reflection papers. In our online courses, trainees get to do lesson plans in various formats prior to the Practicum (and more lesson plans during the Practicum). Those who don’t do the Practicum after the online course get to practice lesson planning and receive feedback. 

As for the Practicum, class observation and teaching practice need to take place in a real setting. This means that our trainees need to teach all 10 hours of the teaching practice portion. Teaching Practice in CELTA is 6 hours and in a real class setting. Lesson plans have to be submitted for our Practicum and CELTA’s. Other online courses with blended option and no accreditation offer “workshop” style of Practicum with peer trainees and basic lesson planning.

4. Why is the teaching practice optional for OnTESOL?

There are many teachers who already have experience and others who are planning to teach abroad where teaching practice or experience is not required by their future employers. For this reason, OnTESOL has separated this module from the FULL Course. However, if you are planning to apply with TESL Canada to obtain the National Professional Certification Standards For Instructors Of English As A Second Or Foreign Language In Adult Programs, teaching practice is a must.

5. Can I teach English without a degree?

Candidates without a degree can register in the 120-hour Advanced TESOL Certificate program. Most of our students have a degree but others are either at college or university, or they do not have any formal qualifications beyond a high school diploma. However, most employers require applicants to have a degree and in most countries a degree is necessary to obtain a work permit.

It is important to highlight that if you are interested in applying for the TESL Canada Professional Certificate Standard 2, you must hold a university degree or equivalent.

6. What type of university degree do I need to get an English teaching job?

The university degree can be in any subject.

A BA in English, Education, and or Linguistics is not usually required for English teaching jobs because an advanced TESOL certification program will give you the skills that you need to follow and adapt an ESL curriculum. A TESOL course recognized by TESL Canada, CELTA, or Trinity CertTESOL will teach you how to create lesson plans using the Communicative Language Teaching Method. You will also get training in grammar and phonology.

TESOL is a very specific subject, so a degree in English, Education, and/or Linguistics would not make much difference in your development as an ESL teacher. However, some entry-level programs in the UAE, Hong Kong, and South Korea prefer to hire teachers who completed a BA in one of these subjects. In addition, some career advancement opportunities are open only to those who have a Master’s degree in one of these subjects on top of their TESOL certification.

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