CAS Letter UK: Requirements, Processing Time & Sample Format
Master the UK CAS letter process for 2026. Learn about the 14-digit reference number, strict 28-day financial rules, processing timelines, and crucial sample formats to ensure seamless visa approval.
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A CAS Letter is a unique, electronic 14-digit reference number issued by a licensed UK university or sponsor to international students. It confirms that you have received an unconditional offer from a UK institution and that you are eligible for the next step in your journey, which is a Study Route Visa application.
CAS Letter UK: What It Is & Why It Is Needed?
The full form of CAS is Confirmation of Acceptance for Studies. This letter serves as an official electronic record issued by licensed UK universities to confirm a student's enrolment. Universities generate this document only after you accept an unconditional offer, making it a mandatory prerequisite for the UK student visa application through UK Visas and Immigration (UKVI).
In the UK student visa application process, it is used for:
- Providing the unique CAS number for UK visa verification by UKVI
- Confirming course details, financial compliance, and sponsor status
- Enabling visa applications within a six-month validity period before the course start date
This letter is a very essential and mandatory piece of evidence for your student visa application. International students must secure this before any visa submission, as no application proceeds without it.
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CAS Letter UK: What does it include?
A CAS letter UK contains precise information shared digitally via email from the university's admissions team. It remains an electronic document, not a physical letter, ensuring secure transmission to students and the UKVI.
| Contents Feature | Description / Role |
|---|---|
| Unique CAS number | Used for automated tracking by immigration officers |
| Sponsor university details | Includes the institution's official UKVI license number |
| Course parameters | Course name, start/end dates, and academic level (UG/PG) |
| Financial ledger | International tuition fees paid, pending amounts, and official deposit proof |
| Academic credentials | English proficiency scores and verified test history |
Source: UK CSI - Student Advice
This structured format allows quick UKVI cross-checks during visa processing.
Did you know that one typo can trigger an automatic UKVI rejection? Because your CAS Letter is transmitted electronically to UKVI, the data on your visa application must flawlessly mirror the university’s registry database.
This is especially critical if your degree includes an integrated placement year. For instance, a simple oversight in course selection can result in a standard 3-year CAS instead of a 4-year timeline meant for sandwich courses in the UK, forcing you into an expensive and stressful visa extension down the line.
Do not leave your visa to chance. Our UK admissions team will perform a meticulous pre-visa data cross-check to verify your tuition receipts, passport spelling, and RQF course levels.
CAS Letter UK: Validity and Processing Time
A CAS Letter is only issued when you have accepted an unconditional offer and paid the required international tuition fee deposit. Delays happen if your academic transcripts, financial proof, or English proficiency scores require further review.
CAS Letter UK Validity
From the date of its issue, a CAS Letter is valid for six months only. It means that you must apply for the UK student visa to join the programme mentioned in the letter within the 6-month validity window. If your CAS Letter expires, you must request a new one from your university.
CAS Letter UK Processing Time
CAS Letter processing time for the UK spans 5–15 working days after complete document submission and approval. Early applicants, outside June to August peaks, see faster turnaround, within 5–10 days, while peak seasons extend to 2–4 weeks.
How to Apply for a CAS Letter from Your UK University?
Follow a straightforward process to get a CAS letter from a UK university, starting right after offer acceptance. Below is the step-by-step application guide for the CAS Letter UK.
- Accept the unconditional offer via the university portal.
- Pay the required deposit, that is, 40% – 50% of the first-year fees.
- Complete the pre-CAS form and upload documents required for the CAS letter, like finances, passport, and TB test.
- Await verification; submit any additional requests promptly.
- Receive the CAS Letter via email once approved.
Note: Contact admissions if delays occur beyond expected timelines due to pending verifications.
AECC Insider Tips: CAS Letter UK Application
Want a surefire way to get your CAS Letter in the UK? Follow these tips from AECC UK counsellors, compiled with their experience and insights.
- Apply 3 Months Early: Submit all final documents at least three months before your course starts. This creates a safety buffer for visa processing and unexpected university delays.
- Track the 10-Day Mark: Wait exactly 10 working days after submission before following up. Send a polite email to the central admissions team with your student ID in the subject line.
- Anticipate Peak Delays: Expect processing to take 2–4 weeks during peak admission cycles, that is, July to September. Budget your accommodation and flight bookings around this extended timeline.
- Pre-Approve Your Draft: Check your ‘Draft CAS’ statement immediately when it arrives in your portal. Minor typos in your name or passport number will cause UK visa rejections.
- Clear Financial Checks First: Ensure your bank statements meet the strict 28-day liquidity rule before hitting submit. Most CAS delays are due to incorrect financial formatting.
Struggling to format your bank statements for the Pre-CAS Review? The number one cause for a university withholding your CAS is a poorly formatted financial statement. Let our finance specialists audit your bank accounts, fixed deposits, or education loan letters to ensure they perfectly align with UKVI standards.
How to Use the CAS Letter for UK Visa Filing?
Upon receiving your CAS Letter, immediately start preparing for the UK visa application. Ensure to apply within the six months before its validity expires. Here’s how to apply for the Study Route visa using the CAS number received by your UK university:
- Gather Supporting Documents: Finances (bank statements/proof of funds), TB test results, and ATAS certificate (if required by your course).
- Apply on the UK Government Student Visa Page: Visit the UK Visas & Immigration (UKVI) Portal and start and submit the student visa application using your CAS reference number.
- Book a Biometric Appointment: Schedule your appointment at a Visa Application Centre (VAC) to provide fingerprints and a photograph.
- Track Application Status Online: Monitor the progress of your visa after your biometric appointment.
- Receive UK Student Visa: Pick up your passport with the visa vignette.
CAS Letter Requirements for UK Student Visa
As per the UK Student Visa Guidance, UK universities verify the following set of core documents post-offer acceptance to issue the CAS letter, with slight variations by institution.
- Passport: Valid with at least one blank page.
- Offer Confirmation: Firmly accepted the unconditional offer of a place on the course.
- Academic Credentials: Official transcripts, consolidated marksheets, and degree certificates.
- English Proficiency*: IELTS Academic, PTE Academic, or TOEFL scores, if required by your course.
- Tuberculosis (TB) Test: Required for students from applicable countries, such as India.
- ATAS Certificate**: An ATAS certificate may be required for your specific research or STEM course.
- Financial Proof: Deposit receipt for tuition or official scholarship/sponsorship letters.
*English: These must be taken at UKVI-approved SELT (Secure English Language Test) centres if the university does not exercise its own institutional assessment exemption. Avoid booking non-certified general exams.
**ATAS: The Academic Technology Approval Scheme (ATAS) is a mandatory UK immigration clearance for international students and researchers in specific STEM courses. This takes at least 30 working days to process.
The Golden 28-Day Rule
A CAS Letter is worthless if the visa application fails due to poor financial timing. Therefore, your funds must sit untouched in your bank account for a minimum of 28 consecutive days before submitting the online visa application. The bank statement must be dated no more than 31 days before your online visa application date.
UK Visa Financial Requirements (Maintenance Funds)
To successfully file your student visa, UK Visas and Immigration (UKVI) requires proof that you have finances to meet the living costs of UK. The funds must be held in your or your parents' bank account for a consecutive 28-day period before your application.
| Compulsory Financial Component | Cost (in NZD) | Core Immigration / Operational Mandate |
|---|---|---|
| Sovereign Student Visa Base Fee | £558 one-time fee | Non-refundable application processing cost for offshore international applicants |
| Immigration Health Surcharge (IHS) | £776 per year | Mandatory annualised payment unlocking full access to the UK's National Health Service (NHS) |
| Inner-London Maintenance Fund | £1,529 per month (up to a 9-month cap: £13,761) | Required living cost benchmark if your main campus site sits inside the Greater London perimeter |
| Outer-London Maintenance Fund | £1,171 per month (up to a 9-month cap: £10,539) | Required living cost benchmark if your main campus site sits outside the Greater London perimeter |
Source: GOV.UK - Student Visa Financial Capacity Requirements · Regulatory Fee Schedule: GOV.UK - Visa Fees Table
Note: Ensure you are referencing the updated UKVI metrics. Avoid outdated third-party websites quoting older figures, which will lead to immediate visa refusal.
Nationality Spotlight: Differential Evidence Requirements for CAS Letter UK
If you hold a passport from a low-risk country, such as the US, Malaysia, Singapore, or Australia, you qualify for differentiation arrangements. You aren't required to upload financial proof or academic transcripts initially. However, UKVI conducts random spot checks. If selected, and you cannot produce perfect bank statements satisfying the 28-day rule within a tight deadline, your visa will be rejected for making a false declaration.
- What it Means: You are not required to upload financial proof or academic transcripts alongside your initial visa application.
- Warning: You are not exempt from the financial rules. UKVI conducts random spot-checks during processing. If you are selected for a spot-check and cannot produce perfect bank statements satisfying the 28-day rule within a strict deadline, your visa will be rejected for making a false declaration. Always have your documents fully prepared before hitting submit.
Can You Re-Use Your CAS Letter UK?
No. A CAS Letter is a strictly single-use document that cannot be recycled under any circumstances. Once the UKVI system processes that unique number, its status changes to ‘Used’ or ‘Burned’. If your visa is refused, or if you change your mind about your university after submitting, that specific CAS is permanently deactivated, and you must request a brand new one.
When Do You Need a Brand New CAS?
- Visa Refusal: If your visa application is rejected, you cannot simply correct the mistake and reapply with the same CAS number. You must ask the university for a new one.
- Changing Universities: If you decide to attend a different UK institution, you must cancel the old application and get a fresh CAS Letter from the new university.
- Withdrawing Your Application: If you notice a major error on your submitted form and decide to withdraw it before a decision is made, the CAS is still burned.
Strict UK University Policies Towards Issuing CAS Letters
Universities are heavily regulated by the UK government. If your visa is refused, the university will conduct a strict internal review of your refusal letter before agreeing to issue a second CAS, ensuring their official visa compliance rating isn't compromised.
| Rule of Thumb: One CAS Number = One Visa Grant |
|---|
Beware of the financial risk of a 'burned' CAS. If your visa is refused due to a financial error, a university's internal compliance panel can take 2–4 weeks to re-vet your profile before issuing a second CAS. This delay causes students to miss their intake entirely.
Whether you need a mistake-free first application or help recovering from a university refusal delay, our senior compliance experts are here to fast-track your paperwork.
CAS Letter UK Sample
A UK student visa CAS letter sample follows a standardised text-based layout from the university's official team. Here is a mock layout for your reference.
CONFIRMATION OF ACCEPTANCE FOR STUDIES (CAS) STATEMENTDate of Issue: 15 June 2026 ---------------------------------------------------------------------- CAS Number: E4G1QT7M56C0G7 ---------------------------------------------------------------------- Family Name: SHARMA ---------------------------------------------------------------------- Course Title: MSc Data Science and Artificial Intelligence ---------------------------------------------------------------------- Academic Qualifications: Bachelor of Science in Computer Science, Mumbai University (First Class Honours) ---------------------------------------------------------------------- Total Course Fees (Year 1): £17,500 ---------------------------------------------------------------------- Accommodation Provided: No ---------------------------------------------------------------------- |
This sample format of a CAS letter for a UK student visa emphasises its role as a visa enabler, not the visa itself.
Timely submission of complete documents required for a CAS letter ensures that you receive your CAS letter UK without hitches, paving the way for seamless visa approval and UK studies. Early action mitigates peak-season delays, keeping dreams on track.
Need help with your CAS process? Register to get matched with your UK expert for end-to-end education consultation, from enrolling on your dream university to getting a CAS Letter and visa approval to reaching the UK university campus.
CAS Letter UK FAQs
The full form of CAS is Confirmation of Acceptance for Studies. CAS is a unique reference number issued by your UK university once you have met all admission conditions and paid any required deposit. It is essential for your student visa application and includes details about your course, fees, and sponsor.
Yes, a UK university reserves all rights to withdraw a Confirmation of Acceptance for Studies (CAS) Letter after it has been issued to you. This is because, as your visa sponsor, they are legally required to report changes or cancel sponsorship if you no longer meet the conditions to study at their institution.
If there is a mistake on your Confirmation of Acceptance for Studies Letter (CAS Letter), it can delay or lead to a refusal of your UK student visa. The UK Visas and Immigration (UKVI) requires the information on your CAS Letter to perfectly match the details on your passport and supporting documents.
No, a Confirmation of Acceptance for Studies (CAS) Letter is strictly tied to a single university and a specific course.
Rule of Thumb: One CAS Number = One Visa Grant.
You can hold multiple CAS letters from different institutions, but you can only use one CAS number for your Student Visa application.
No, a Confirmation of Acceptance for Studies (CAS) Letter does not guarantee a UK Student Route visa. While it is a mandatory document for your UK Student Visa application, the final approval is solely at the discretion of UK Visas and Immigration (UKVI). UKVI assesses your entire application against all standard immigration requirements and then decides whether or not to proceed with your profile.
The processing time of the CAS Letter at UK universities is 5 to 10 working days. A UK university will issue your Confirmation of Acceptance for Studies (CAS) Letter after you have submitted all your required documents. However, this timeline only begins after you have met several crucial prerequisites.
No, a CAS Letter is not reusable. It is a strictly single-use digital voucher. Once a CAS number is entered into a submitted visa application, it is permanently linked to that application. If your visa is refused or if you choose to change your university, that CAS becomes invalid, and you must request a completely new one from your institution.
Trusted Expertise
About the Author
Published and reviewed by AECC counsellors who guide students through every step of their study-abroad journey.
Published by Devi Mukherjee
UK & Ireland Education Specialist | 20 Years Advising International Students
Devi Mukherjee has been advising students on study in the United Kingdom and Ireland for 20 years. She has worked through several significant shifts in UK immigration policy, including the move from Tier 4 to the Student visa, the introduction of the Graduate Route, and the changes to English language test requirements that have affected applicants considerably over the past three years.
Devi is particularly good at bridging the gap between what official guidance says and what it means in practice. UK Home Office guidance is written for a general international audience. Devi advises students working with specific academic certificates, bank statements and English language test scores, and the specifics matter. She knows where the complications arise and what to do about them.
Her articles on UK and Irish universities are written for students who are not simply asking whether they are eligible, but whether this is the right choice given their academic background, budget and what they want to do after graduation. That is a different question and it requires a different kind of answer. She holds an MSc in Physics and is based at AECC's Gurgaon office.
