CAS Letter Explained: What International Students Need to Know

CAS Letter Explained: What International Students Need to Know

A CAS (Confirmation of Acceptance for Studies) is the single most important document in your UK Student Visa application. Without a valid CAS issued by a licensed UK university, the Home Office cannot consider your visa. This guide explains exactly what a CAS is, how to get one, how to read it, and the errors that cause visa refusals.

What Is a CAS?

A CAS is a 14-digit reference number generated on the UKVI Sponsor Management System (SMS) by a university that holds a Student Sponsor Licence. It is not a physical letter — it is an electronic record the Home Office uses to confirm:

You have an unconditional offer at a licensed UK university

You meet the university's academic and English requirements

Your course details, dates and fees

The deposit you have already paid

Your personal details (name, DOB, passport, nationality)

When the university generates your CAS, they send you an email containing the 14-digit number plus a CAS Statement (PDF) summarising all the data on the record. You upload the CAS number when applying for your visa.

When Do You Get a CAS?

You get a CAS after all of the following are true:

You have an unconditional offer (all conditions met)

You have paid the tuition deposit (typically GBP 2,000-5,000)

You have submitted any pre-CAS documents the university requests (passport, academic transcripts, English test, financial statement)

You have completed any credibility interview the university requires

You have confirmed your intent to enrol via the university's CAS request form

Typical CAS issue time: 3-15 working days after the last item is completed. Peak season (June-August) can extend to 3-4 weeks.

How to Read a CAS Statement

Every CAS Statement contains the following fields. Check each one against your passport and offer letter before applying for your visa:

Field	Check

|---|---|

CAS Number14 digits, starts with "E4"Sponsor Licence NumberMatches gov.uk Register of Licensed SponsorsSponsor RatingMust be "Track Record" or "Probationary" (not revoked)Course NameExactly matches your offer letterCourse LevelRQF 6 (Bachelor's), RQF 7 (Master's), RQF 8 (PhD)Course Start DateRealistic travel + visa processing windowCourse End DateWithin your visa allowanceTotal Tuition FeeFirst year only (or whole course if under 12 months)Tuition Fee Already PaidDeposit amount, must match your receiptAccommodation Fee PaidUp to GBP 1,583 deductible from living costEnglish Language Assessment"Internal assessment" or test name + scoreAcademic Qualifications UsedLists the degree/diploma that secured the offer

Common CAS Errors That Trigger Visa Refusals

Name spelt differently to passport — request a CAS reissue immediately

Wrong date of birth — even one digit triggers refusal

Passport number outdated — if you renewed after the CAS, ask for a new CAS

Course start date already passed — university must reissue with new date

Tuition deposit on CAS does not match your receipt — must match to the penny

Sponsor rating shows revoked — the licence was withdrawn; you cannot use this CAS

English test score below the course requirement — university must add MOI letter or new test

Accommodation deduction missing — you forfeit up to GBP 1,583 reduction in financial requirement

Always reply to the CAS email confirming the data is correct before booking your biometrics appointment. A reissued CAS takes 2-5 days; a refused visa takes 28 days to overturn (and may not be).

Sponsor Licence Ratings

The UK Home Office rates every Student Sponsor:

Track Record — full rating, longstanding compliance

Probationary — newer sponsors, still fully able to issue CAS

Revoked — licence withdrawn; CAS cannot be used, refund your deposit

Always check your university's status on the gov.uk Register of Licensed Sponsors before paying any deposit. The register is updated weekly.

CAS and Pre-Sessional English

If your offer includes a pre-sessional English course, you receive one combined CAS covering both the pre-sessional and the main degree, provided the gap between them is under 28 days. Two separate CAS = two separate visa applications = avoid where possible.

CAS Validity and Reuse

A CAS is valid for 6 months from issue

A CAS can only be used once — if your visa is refused, the university must issue a new CAS

You can apply for your visa up to 6 months before the course start date

You cannot enter the UK earlier than 1 month before the course start date (or 1 week if the course is under 6 months)

What If My CAS Is Withdrawn?

A university can withdraw a CAS at any time before you receive your visa. Common reasons: you did not pay full deposit within the deadline, academic documents failed verification, missed a credibility interview, or stopped responding to admissions emails. If your CAS is withdrawn after a visa application, UKVI will refuse the application. The deposit is usually refundable per the university's terms.

Related Reading

UK student visa financial requirements 2026

UK student visa requirements 2026

UK student visa do's and don'ts

Conditional vs unconditional offer UK

UCAS Clearing 2026 for international students

*Sources: UKVI Sponsor Guidance for Student Sponsors (gov.uk, accessed 2026), Appendix Student rules, UKCISA CAS guidance, Register of Licensed Sponsors (gov.uk).*