Understanding UK’s CAS Letter Requirements and Deadlines

For international students seeking to study in the United Kingdom, the Confirmation of Acceptance for Studies (CAS) is one of the most critical pieces of documentation. Issued by UK-approved educational institutions, this digital document acts as a green light to begin the visa application process. Without a CAS, applying for a UK Student Visa (previously Tier 4) is impossible.

In 2025, the UK continues to attract hundreds of thousands of students globally. However, navigating the administrative process around CAS letters requires preparation, timing, and a full understanding of UK Visas & Immigration (UKVI) rules. This detailed guide explains everything an international student needs to know about the CAS letter: its purpose, requirements, deadlines, and key mistakes to avoid.

What Is a CAS Letter?

The Confirmation of Acceptance for Studies (CAS) is a virtual document (not a paper letter) issued by a UK educational provider (sponsor) to confirm that an international student has been accepted onto a valid course and meets the criteria for a Student Visa under UK immigration law.

The CAS is stored in a UKVI database and contains a unique reference number that the student includes in their visa application.

Who Issues the CAS?

Only institutions with a UKVI sponsor license (typically universities, colleges, and certain pathway providers) can issue a CAS. This includes:

• Universities (e.g., University of Manchester, King’s College London)

• Pathway providers (e.g., INTO, Kaplan, Navitas)

• Further education colleges (for courses above RQF Level 3)

When Is a CAS Issued?

A CAS is typically issued after the student meets these conditions:

• Received and accepted an unconditional offer

• Paid the required deposit (usually £3,000–£5,000 or a percentage of the total tuition)

• Provided satisfactory financial documentation

• Passed required English language tests (IELTS, PTE, etc.)

• Completed a pre-CAS questionnaire or credibility interview (if requested)

What Information Is in a CAS Letter?

A CAS includes all critical information required by UKVI:

• Personal details (full name, date of birth, nationality, passport number)

• Institution sponsor details (name, sponsor license number)

• Course details (name, level, length, start/end dates)

• Tuition fees (total amount, amount paid)

• Accommodation fees paid (if applicable)

• English proficiency confirmation

• Unique CAS reference number

Students must cross-check all information carefully before submitting their visa application.

CAS Validity Period

Once issued, the CAS is valid for six months, and the student must apply for a Student Visa within this period. However:

• You cannot apply for a visa more than six months before your course start date if applying from outside the UK

• If applying inside the UK, you must apply before your current visa expires

Financial Requirements to Get a CAS

To be eligible for a CAS, the student must prove financial ability to support themselves during their studies.

Financial proof includes:

• Tuition fees (either fully paid or partially paid + proof of ability to pay the rest)

• Living expenses for up to 9 months:

  • £1,334/month for London-based institutions

  • £1,023/month elsewhere in the UK

• Funds must be held in a bank account for at least 28 consecutive days

• Bank statements must be dated within 31 days before the CAS is issued

Common Mistakes to Avoid

International students frequently encounter CAS-related delays due to:

• Name mismatch between passport and CAS

• Providing bank statements in incorrect format

• Submitting expired financial documents

• Delaying deposit payment

• Submitting conditional offers instead of unconditional

• Ignoring pre-CAS assessments or failing the credibility interview

Each of these issues can delay your CAS or invalidate it altogether.

Pre-CAS Questionnaire and Credibility Interviews

Many universities, especially in high-risk visa refusal countries, now require students to:

• Complete a pre-CAS questionnaire (covering financial plans, academic background, future goals)

• Attend a credibility interview (via Zoom or in-person)

This is to ensure the student is genuinely pursuing education and not entering the UK for non-academic reasons.

Failure to pass these steps will delay or cancel your CAS issuance.

How Long Does It Take to Get a CAS?

On average, once all documents are approved and fees are paid, a CAS is issued within 5–10 business days. However, during peak intake seasons (July–September and November–January), it may take longer.

Students are advised to complete all requirements at least 12 weeks before the course start date to avoid complications.

Can You Use One CAS for Multiple Courses?

No. A CAS is specific to one course and one institution.

If you:

• Change your course,

• Change your institution, or

• Miss your course start date,

You’ll need a new CAS. Always notify your institution of any changes immediately.

Can You Defer and Reuse the Same CAS?

No. If you defer your studies to a later intake (e.g., from September to January), your CAS becomes invalid. You’ll need:

• A new unconditional offer

• A new pre-CAS check

• Possibly updated financial documents

Universities often charge an administration fee to issue a new CAS after deferral.

What Happens If You’re Refused a Visa?

If your visa application is refused, the institution will need to:

• Review the refusal letter

• Decide if a new CAS can be issued (depends on refusal reason)

• Possibly conduct another interview or document check

Be transparent with your university about any refusal, as UKVI compliance is strict and can affect future CAS issuance.

Deadlines to Watch in 2025

Each university sets its own CAS deadlines, typically 8–12 weeks before the course start date. Some sample guidelines:

Always check with the International Admissions Office directly for the most updated dates.

CAS for Short Courses and Pre-Sessional English

If you are applying for:

• Pre-sessional English courses

• Foundation or diploma courses

• Short-term study modules

Your CAS may be shorter in validity and may not allow for visa extension. These CAS letters are still subject to the same UKVI rules and should be treated seriously.

Some students get a combined CAS that includes pre-sessional + degree program. Ask your university whether this applies to your case.

Can You Work Using a CAS?

Once you receive a visa based on a valid CAS, you can work in the UK under these limits:

• During term time: Up to 20 hours per week (part-time)

• During holidays: Full-time allowed

• Postgraduate students working on dissertations are considered “in term”

• Dependants of postgraduate students (on eligible courses) can work full-time

Your CAS will confirm your study dates, which determine these work restrictions.

What Happens After You Arrive in the UK?

After arrival:

1. Collect your BRP card within 10 days from your local Post Office.

2. Register with your university using your visa and BRP.

3. Confirm your CAS number matches all official records.

Failing to do this may result in sponsorship withdrawal, which leads to visa cancellation.

Conclusion

The CAS process is one of the most important, yet misunderstood, steps in studying in the UK. It requires attention to detail, early preparation, and precise documentation. In 2025, UKVI maintains strict compliance standards, and universities are equally cautious. Whether you’re studying a Master’s degree in London or a diploma course in Scotland, the CAS letter is your legal key to a successful visa application.

To succeed:

• Stay in constant communication with your institution.

• Meet all deadlines early.

• Double-check all document accuracy.

• Don’t treat the CAS as just another form it’s the foundation of your legal study stay in the UK.

With the right preparation, international students can confidently approach this phase and start their journey toward academic success in the United Kingdom.