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What is CAS? Your Complete Guide to the Confirmation of Acceptance for Studies

By Wayne Chai
6 min read

Student holding a CAS letter while preparing a UK Student Visa application

Introduction

If you are planning to study in the United Kingdom, you will quickly come across one small acronym with a very big role: CAS. So, what is CAS? In short, it is the Confirmation of Acceptance for Studies, a document that sits at the heart of every UK Student Visa application. Without it, your Visa application cannot even begin. Yet many students only learn about the CAS late in their application journey, which can lead to unnecessary stress, delays, or even Visa refusals. This guide explains what a CAS is, how you get one, what information it contains, and the latest facts every International Student should know before applying.

Why This Matters

The UK remains one of the world’s most popular study destinations, and the Student Visa route is the gateway for most International Students. Because the CAS is a mandatory requirement for that Visa, understanding it early can save you weeks of waiting and protect you from costly mistakes. Errors in your CAS details, applying with an expired CAS, or misunderstanding the financial requirements linked to it are among the most common reasons Student Visa applications run into trouble. In other words, knowing what a CAS is and how to handle it correctly directly affects whether you arrive on campus on time.

International Student discussing a UK University application

Main Topic: What is CAS?

A Confirmation of Acceptance for Studies (CAS) is an electronic document that generates a reference number required in order to apply for a study Visa. It is not a paper certificate you frame on a wall. Instead, it is a unique number which confirms you have been accepted on a course of study in the UK, generated using the Home Office’s system, and it is essential in order to make a successful Visa application.

Only UK institutions that hold a valid student sponsor licence can issue a CAS. When your chosen university assigns you a CAS, it electronically shares your details with UK Visas and Immigration (UKVI). When you later submit your Student Visa application, you enter your CAS number, and the caseworker matches your application against the record your university created. This is why accuracy matters so much: any mismatch between your documents and your CAS record can cause problems.

A typical CAS statement includes:

  • Your personal details (name, date of birth, passport number)
  • Your course title, level, start and end dates
  • Your tuition fees and any amounts already paid
  • Details of the qualifications and English test results used to admit you
  • Your sponsor institution’s licence number

Supporting Information: How Do You Get a CAS?

The CAS process follows a fairly standard sequence at most UK universities:

1. Receive and accept an unconditional offer. A CAS can only be issued once you have met all academic and English language conditions.
2. Pay any required deposit. Most universities ask for a tuition fee deposit before issuing a CAS.
3. Complete the CAS request or pre-CAS checks. Many institutions run a credibility check or ask you to confirm your details on a draft CAS. Check everything carefully because a small typo can create a big problem later.
4. Receive your CAS number by email. This usually arrives within a few days to a few weeks, depending on the university and the time of year.
5. Apply for your Student Visa using the CAS number, along with your financial evidence, passport, and other supporting documents.

Timing is important here. You can use your CAS number to apply for a Visa up to six months before the date your course is due to start if you are applying from outside the UK, or up to three months before your course starts if you are applying from inside the UK. Your CAS also has a shelf life, hence it must still be valid (less than six months old) when you submit your Visa application, and each CAS can generally only be used for one application.

International Student preparing documents for studying in the UK

Tips for Students: Things to Consider Before Your CAS Arrives

Beyond the paperwork itself, here are some practical points worth thinking about while you wait for your CAS:

Prepare your finances early. The 28-day rule catches many students off guard. Set aside your maintenance funds well before you plan to apply, and avoid letting the balance dip below the required amount.
Check every detail on your draft CAS. Confirm that your name, passport number, course dates, and fee amounts are correct. Report errors to your university immediately.
Do not book non-refundable flights too soon. Visa processing times vary, especially during the August–September peak. Wait until your Visa is granted before making major commitments.
Understand what your CAS does not do. A CAS is not a Visa and not a guarantee of one. You must still meet all Student Visa requirements independently.
Keep your documents consistent. The qualifications and English test listed on your CAS should match the evidence you submit with your Visa application.

Student preparing a CAS letter for a UK Student Visa application

FAQ: What is CAS?

How long does it take to receive a CAS?

It varies by institution, but most universities issue a CAS within a few days to a few weeks after you meet all conditions and pay your deposit. Peak season (June–August) can be slower.

Can I use one CAS for multiple Visa applications?

No. A CAS is generally valid for a single Visa application. If your application is refused or your CAS expires, you will need to request a new one from your university.

What happens if my CAS contains a mistake?

Contact your university straight away. Sponsors can add notes or, in some cases, issue a corrected CAS. Never apply for a Visa with details you know to be wrong.

Is a CAS the same as an offer letter?

No. An offer letter confirms your admission; the CAS is a separate electronic record created specifically for your Visa application after you accept an unconditional offer.

Do I need a physical CAS letter for my Visa application?

No. You only need the CAS reference number, although most universities send a CAS statement by email so you can check the details.


Summary

So, what is CAS? It is the electronic Confirmation of Acceptance for Studies with a unique reference number issued by your UK University that unlocks your Student Visa application. To get one, you need an unconditional offer, a paid deposit, and accurate documentation. Once issued, your CAS is valid for six months, and you can apply for your Visa up to six months before your course starts. With Visa fees, health surcharges, and maintenance requirements all rising in 2025–2026, early preparation is the single best thing you can do for a smooth journey to the UK.

Ready-to-Appy

If you would like guidance on your UK University application or CAS process, the team at AUG Student Services is happy to help, thus feel free to reach out for a free consultation.