The Trinity Diploma in Teaching English to Speakers of Other Languages (DipTESOL) is an advanced Level 7 qualification for experienced English language teachers who want to develop their professional knowledge, teaching expertise and career opportunities.
DipTESOL is a Master's-level qualification recognised by employers in the UK and internationally, including British Council-accredited institutions.
It combines advanced theoretical knowledge with practical teaching, research and reflective professional development.
Who is DipTESOL for?
DipTESOL is designed for experienced English language teachers who want to:
Progress into senior teaching or academic management roles.
Become teacher educators, mentors or trainers.
Develop advanced knowledge of language teaching and learning.
Strengthen their classroom practice through research and reflection.
Support the professional development of less experienced teachers.
Pursue further professional or academic development.
The qualification is intended for practising English language teachers rather than people entering the profession for the first time.
What are the entry requirements?
Applicants should:
Have substantial experience teaching English to speakers of other languages, usually approximately 1,000 hours of classroom teaching.
Have English language proficiency at CEFR Level C1 or above.
Ideally hold a first degree or equivalent experience.
Ideally hold an initial TESOL teaching qualification, such as Trinity CertTESOL, or have equivalent teaching experience.
The teaching experience recommendation helps ensure that applicants have the practical knowledge needed to complete the qualification.
However, the number of teaching hours is not the only consideration. Trinity-validated course providers assess applicants through an initial assessment to determine whether they have the knowledge, experience and skills needed to complete DipTESOL successfully.
Applicants without previous formal TESOL training or assessed teaching experience may require additional screening.
What will I learn?
DipTESOL develops advanced knowledge and practical skills in language teaching, research, phonology and classroom practice.
The qualification consists of four assessed units.
| Unit | What it covers |
|---|---|
| Unit 1: Language – Theory and Practice | Language awareness, theories of language learning and teaching, and their application to classroom practice. |
| Unit 2: Research – Developmental Enquiry | Classroom-based research, reflective practice and professional development. |
| Unit 3: Phonology – Classroom Applications | English phonology, pronunciation teaching and applying phonological knowledge to classroom practice. |
| Unit 4: Classroom Teaching – Lesson Planning, Delivery and Evaluation | Advanced lesson planning, observed teaching, classroom delivery and critical self-evaluation. |
The qualification places particular emphasis on applying theory and research to your own teaching context.
How long does DipTESOL take?
DipTESOL has a total qualification time of 600 hours, comprising:
150 guided learning hours, including structured training and supervised activities.
450 hours of independent study, including research, reading, lesson preparation and assessment work.
Courses are delivered by Trinity-validated course providers.
Part-time and blended study options may be available, depending on the provider.
Candidates have three years to pass all four units, calculated from the date of their first external assessment or moderation.
How is DipTESOL assessed?
DipTESOL is assessed through four units combining written work, research, interviews and observed teaching.
The assessment structure was updated from April 2026:
Unit 1: Language – Theory and Practice
Candidates complete a three-task written assignment demonstrating their understanding of language and its application to teaching.
Before submission, candidates take part in a pre-assessment discussion with a course tutor.
The assignment is then submitted to Trinity for external assessment.
Unit 2: Research – Developmental Enquiry
Candidates complete research-based tasks exploring their professional practice and development.
The unit focuses on classroom research, critical reflection and applying findings to teaching.
Unit 3: Phonology – Classroom Applications
Candidates complete a 30-minute online interview with a Trinity examiner.
The interview includes:
A presentation and discussion about a phonological teaching activity or approach.
Transcription and analysis of the candidate's own classroom language.
A discussion about phonological theory and classroom practice.
Unit 4: Classroom Teaching – Lesson Planning, Delivery and Evaluation
Candidates complete five teaching observations:
One unassessed diagnostic lesson.
Four assessed teaching observations.
Assessment includes lesson planning, classroom teaching, reflection and evaluation.
The unit includes an externally assessed teaching observation.
How is DipTESOL graded?
The overall DipTESOL qualification is awarded at two levels:
Pass
Pass with Distinction
- To achieve a Pass, candidates must obtain at least 50% of the available marks in each of the four units and meet any additional unit-specific pass requirements.
- To achieve a Pass with Distinction, candidates must obtain at least 80% in three of the four units, including Unit 4, and at least 50% in the remaining unit.
- Individual unit results may also be reported using Distinction, Merit, Pass and Fail bands.
- Candidates who do not pass a unit may be eligible to resubmit within the qualification's three-year assessment period, subject to Trinity's requirements and applicable fees.
Is DipTESOL internationally recognised?
DipTESOL is regulated at Level 7 on the UK's Regulated Qualifications Framework (RQF).
It is recognised internationally as an advanced English language teaching qualification and can support progression into roles such as:
Senior teacher.
Director of studies.
Academic manager.
Teacher educator or trainer.
Mentor or examiner.
DipTESOL may also support applications for further academic study. Recognition for academic credit or entry to a particular programme is determined by the receiving institution.
For more information, see Are Trinity TESOL qualifications recognised internationally?
How much does DipTESOL cost?
Course fees are determined by individual Trinity-validated course providers.
Fees may vary depending on the provider, location and delivery arrangements.
Trinity examination fees may also apply.
Contact your chosen provider for a full breakdown of course fees, assessment fees and payment arrangements.
How do I apply for DipTESOL?
DipTESOL courses are delivered by Trinity-validated course providers around the world.
To apply:
Find a Trinity-validated provider offering DipTESOL.
Contact the provider to discuss entry requirements, teaching experience, course dates, fees and study options.
Complete the provider's application and initial assessment process.
For further guidance, see How to find a Trinity-validated TESOL course provider.
Further information and documents
The following official Trinity documents provide additional information about DipTESOL:
DipTESOL factsheet – A summary of the qualification, intended audience, entry recommendations, course structure and professional progression opportunities.
DipTESOL Qualification Specification and Assessment Information (April 2026) – Detailed information about the four units, assessment requirements, grading criteria and qualification rules.
See also:
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