Verified against official sources — 30 Oct 2026
Confirmation of Acceptance for Studies (CAS): What It Is and How It Works
NEW Published 30 October 2026
The reference number that unlocks a UK Student visa application — who issues it, what it proves, its 6-month deadline, and what it carries about your course and fees.
A CAS is a reference number your education provider sends you once they have offered you a place on a course. You need a CAS before you can apply for a Student visa, you enter the reference number on your application, and you must apply within 6 months of receiving it. Your course fee for one academic year — a core part of the money you must show — is stated on the CAS, and if you later apply for a Graduate visa, you will need the same CAS reference number again.
SECTION 01What a CAS Proves
GOV.UK's Student visa pages describe the CAS in a single consistent way: "To prove this [an unconditional offer], your education provider will send you a reference number (called a Confirmation of Acceptance for Studies (CAS)) once they've offered you a place on the course." Three facts sit inside that sentence. The offer must be unconditional. The provider must be your course provider — a licensed student sponsor. And the CAS is a reference number you enter on your application, not a paper certificate you post.
Because the CAS is the proof of the offer, there is no version of the Student route that starts with the visa application and finds a course later. The sequence is always: offer first, CAS second, application third.
SECTION 02The 6-Month Deadline
GOV.UK states the deadline twice, for outside-UK and inside-UK applicants alike: you must apply for your visa within 6 months of receiving your CAS. An unused CAS does not roll over — if the 6 months pass, the application cannot proceed on that reference, and the sponsor would need to issue a new one. Treat the CAS date as the start of your application clock: the money evidence (28 days of held funds, ending within 31 days of applying), the ATAS certificate where needed, and the TB certificate where needed all have to be sequenced inside the window the CAS opens. Those timings are covered in our TB test and ATAS guide and the financial requirement guide.
SECTION 03What the CAS Carries: Your Course Fee
The CAS is also a financial document. GOV.UK's money guidance states that the course fee you must show — the fee for one academic year, up to 9 months — is the amount on your CAS: "The amount you need to pay will be on your Confirmation of Acceptance for Studies (CAS)." The same is true if you are boarding at a residential independent school, where boarding fees replace the standard living-costs figure and are likewise stated on the CAS. Read your CAS when it arrives: the fee figure on it is the figure your financial evidence will be judged against, and a CAS that shows the wrong course, the wrong fee, or the wrong personal details is a problem to raise with your sponsor before you apply, not after.
SECTION 04One CAS, One Course, One Sponsor
A CAS is issued by one provider for one course. GOV.UK's Graduate visa guidance shows the same specificity from the other end of the journey: if your provider let you change course without a new visa, it is the course you changed to that you must have completed. And for dependants, the application runs off your application number (a Global Web Form or Unique Application Number) — the family's applications are tied to yours, which is itself tied to your CAS. If you change your mind about the university after a CAS is issued, you are not amending a detail: you are restarting the sponsor relationship, and the new provider must issue its own CAS before you can apply on that basis.
SECTION 05Keep the Number: You Will Need It Again
The CAS reference outlives the Student application. GOV.UK's Graduate visa document list requires "your Confirmation of Acceptance for Studies (CAS) reference number from when you applied for your Student visa or Tier 4 (General) student visa" — and adds practical advice: if you cannot find it, ask your education provider what it is. Keep the CAS reference with your passport details and decision letter from the day it arrives; years later is the wrong time to reconstruct it.
FAQFrequently Asked Questions
Is a CAS a guarantee my visa will be granted?
No. The CAS proves one eligibility condition — an unconditional offer from a licensed sponsor. The money, English and other requirements are assessed separately, and UKVI decides the application as a whole.
Can I apply for my visa before my CAS arrives?
No. GOV.UK states you need a CAS before you can apply, and you enter the reference number on the application itself.
My CAS is five months old and my funds are not ready. What happens at six months?
GOV.UK requires you to apply within 6 months of receiving the CAS. If that window closes first, the application cannot proceed on that reference — you would need your sponsor to issue a new CAS.
I have offers from two universities. Can I hold two CAS numbers?
GOV.UK's pages do not describe holding multiple CAS references for one application; each application rests on the CAS from the provider whose course you will take. Choose the course first, then take the CAS from that provider, and apply on it.
Where is my course fee officially stated?
On your CAS. GOV.UK's money guidance says the amount you need to pay for one academic year will be on your Confirmation of Acceptance for Studies.
Official references and verification status
These official references were accessed and checked on 30 October 2026, and this guide's claims were verified against them (see the accompanying sources file). One honest limit: GOV.UK's applicant-facing pages describe what a CAS is and the rules around it, but the sponsor-side mechanics of issuing one (sponsor licence duties, CAS assignment systems) sit in sponsor guidance this guide does not summarise — nothing here describes how a university decides to issue a CAS.
General educational information, not individualized legal or immigration advice. Follow the official GOV.UK instructions for your own situation, and consult a qualified UK immigration adviser regulated in the UK for advice about an individual case.
General information only. This guide is based on official sources publicly available and checked on the date shown on this page. Visa rules change, and consular and USCIS officers decide every case on its own facts — nothing here is a confirmation or a guarantee for your individual case, and this is not legal advice. Always confirm the current requirement on the official page linked in this guide before you act, and consider a qualified immigration attorney for your specific situation.