250-hour TESOL Diploma for Experienced ESL Teachers

When considering this program, you need to be particularly careful if you hold a passport which is not from the major English-speaking countries like the US, UK, Australia, Canada & New Zealand. No matter what your mother tongue or level of fluency, most TESOL employers will immediately categorise you as a “non-native English speaker” (NNES) which will bar you from most TESL jobs despite this certification.

And speaking of the certification, please be aware that in addition to the huge hidden disadvantage of being an NNES, you will have to jump through quite a few extra hoops -including unexpected post-course costs - to get your certificates verified by a Canadian public notary. Similarly you have to initiate separate processes - and yes, more fees - to get the touted TESL Canada and ACTDEC accreditation officially. Not only that, to obtain the TESL Canada certification, after filling a form, paying registration and annual fees for membership, students must then independently source and organise, either a 20-hour online practicum for Level 1 or a 50-hour in-person practicum at accredited centre for Level 2 certificate.

In stark contrast, Gold-standard, internationally respected programs like Cambridge CELTA/DELTA or Trinity CertTESOL include their global recognition and practical components seamlessly.

Add to this the fact that OnTESOL’s 'free lifetime job assistance' operates as a passive directory rather than active, hands-on recruitment. There are some other things you can miss while reading OnTESOL’s main promotional materials highlighting high global salaries and ease of hiring, Specifically, the aforementioned passport filter but most surprisingly, their terms include an asymmetrical intellectual property clause: students are legally barred from sharing their own original assignments with future employers or tutors, yet OnTESOL retains the right to use that student work for their own advertising and educational materials.

Academic-wise, the initial course layout was opaque and poorly organized. My first tutor responded to queries only in monosyllables, making it an immense struggle to gather clear information. To their credit, management was gracious when I formally complained; they granted course extensions and assigned me an excellent second tutor, the highly competent and cooperative Ms. Margaret Hurley who helped me learn a great deal about lesson-planning frameworks.
While you can absolutely learn here if you advocate for yourself, and fall in the category of a native English speaker, the program requires serious structural revision and proactive career support. Non-native English speakers should carefully review these buried parameters before purchasing.

UPDATE (August 2026): After posting this review, a Student Advisor named Dan Bailly contacted me and explicitly stated that if I keep my review up, they will refuse to provide a job reference to my future employers and in fact give negative feedback to them. Prospective students should be aware that this company uses reference extortion to suppress negative feedback highlighting their real policies as well as the true career prospects for non-native English speakers.

It took me some time to find the right TESOL course. Now I know I made the right decision choosing the 250-hour TESOL diploma from ONTESOL. The support was great, my tutor answered all my questions and helped me when I needed it. The assignments and tasks were hard work but the best way to learn and to practice. I would recommend it to anyone that is in doubt and does not know which course to choose. This one is the right choice!
I am going to enroll in another course from ONTESOL (Teaching English Online Certificate)! and I am sure it is going to be another great experience. Thank you ONTESOL!

ONTESOL provides a very productive course with in-depth knowledge of the subject matter. I am very satisfied with the overall experience. My mentors, Margaret Hurley and James Green, were both very supportive and are very intellectual. The entire course is very carefully built keeping in mind how a candidate would need to progress towards the end goal. I am a teacher, and nobody can understand the course development better than me. The course is very effectively structured so that students can move step by step to enhance their overall knowledge.

Both my mentors were very supportive and were readily available in case of any difficulties that came up during the course. They explained everything very nicely which made all the concepts clear to me.

I would highly recommend ONTESOL if you wish to learn from home.

The ONTESOL 250-Hour Diploma was a comprehensive program that well prepared me to meet the demands of serving as an ELT instructor and in working in the field of TESOL. I enjoyed the content related to pronunciation and teaching methodology. I appreciated the assignments within the course as they mirrored real-world tasks and skill development. The course provided a lot of practical information that I continue to reference in my daily career. If you are looking for a comprehensive course with practical training elements, I would recommend the 250-HOUR TESOL diploma.

I did the 250-hour TESOL Diploma, and 20- hour Specialist certificate courses (Teaching Young Learners, Business English, and Teaching IELTS). Margaret was my tutor for the Diploma course. She is highly experienced. She gave detailed explanations to questions, and provided constructive feedback. Talking about the course material, I think anyone can understand it. It was easy and concise.
For the Specialist courses, James was my tutor. He’s experienced and also responded to queries promptly. I think Teaching IELTS remains the best. It covered all aspects of the IELTS Exam preparations, and has wonderful tips that can help any student to succeed.
I must say that it is worth it for anyone aspiring to be a good ESL teacher to go for any of the OnTESOL courses. They are carefully designed to meet different needs with regards to teaching. Above all, you are going to meet wonderful people that would help you succeed. I remembered when I couldn’t meet up with the deadline due to accident that I had, Sebastian and others were there to help. I have already gotten my diploma and certificates but they are still willing to help with job search.
In general, I recommend Ontesol to anyone who wants to be a wonderful ESL teacher.

Clare Linton and her colleagues were extremely helpful for me in terms of helping me tailor my resume and steering me towards suitable jobs that fit my needs. I would highly recommend Mrs. Linton and the team at ONTESOL in terms of helping one find suitable jobs both domestically and internationally.

I recently completed my 250 hour TESOL Diploma. I could not be more satisfied! The course was comprehensive and provided in-depth information on creating lesson plans and teaching grammar, vocabulary, speaking, and pronunciation. My tutors were extremely helpful in guiding me in the right direction by providing ample support which allowed me to become more confident in making lesson plans and grow in areas I was challenged. Lastly, TESOL's job placement assistance is another plus, as they provided me with a lot of information and helped me find a job that I am excited to start in September!

Having a TESOL certification opened up a lot of doors for me. I initially only did it to meet the requirements for my existing teaching job, but it did make finding a job in a language school much easier.

I completed the TESOL program in eight months and, while I did find it somewhat challenging to complete it on time, it was fairly doable. The methodology module was fairly challenging, but I found the grammar and phonology ones alright.

The tutors were helpful and they answered their emails quickly, and additionally provided more explanations when I asked. Assignment-wise, I would say that some of the assignments require you to pay close attention to the instructions and execution, and those assignments were among the most challenging ones. Luckily, it is allowed for students to re-take an assignment if they have failed the first time.