DU CSAS Phase 1 Registration 2026: Step-by-Step Guide to Fill the Application Form

If you’ve cleared CUET UG 2026 and want to study at Delhi University, your very first task is completing DU CSAS Phase I registration. This is the stage where you create your admission profile, enter your academic and personal details, upload documents, and pay the registration fee — before you can even think about choosing colleges and courses.

For a first-time visitor, the CSAS portal can feel overwhelming: multiple sections, dropdowns, document uploads, and a payment gateway, all with strict deadlines. This guide walks you through every screen and every field of DU CSAS Phase I registration, so that even if you’ve never opened the portal before, you’ll know exactly what to expect and how to avoid common mistakes.

What Is DU CSAS?

The Common Seat Allocation System (CSAS-UG) is Delhi University’s centralised online portal for all undergraduate admissions. Instead of applying to individual colleges, every applicant registers once on CSAS, and admission to all UG programmes across DU’s constituent colleges happens through this single system, based entirely on CUET UG scores.

Why Phase I Is Mandatory

Phase I is the registration and document-submission stage. You cannot move on to Phase II (preference filling) or Phase III (seat allocation) without completing Phase I — including successful fee payment. Simply appearing for CUET UG is not enough; DU treats your application as valid only once Phase I registration is complete and confirmed.

Common Mistakes Students Make

• Waiting until the last day, when the portal and payment gateway get overloaded
• Entering a name, date of birth, or category that doesn’t match the CUET application form
• Uploading unclear or wrongly formatted documents
• Not reading each screen carefully before clicking “Submit”
• Forgetting that Phase I basic details often cannot be edited once submitted, except during a specific correction window

What Happens in Phase I?

Phase I registration is made up of several connected steps. Here’s a quick overview before we go deeper:

• Registration: Creating your login using your CUET application number and setting a password
• Profile creation: Your basic academic and personal information gets auto-fetched from the CUET database
• Personal details: Filling in details like address, parents’ names, nationality, and contact information
• Academic details: Entering Class 10 and Class 12 information, including subjects and marks
• Reservation details: Declaring your category (SC/ST/OBC-NCL/EWS/PwBD, etc.), if applicable
• Supernumerary quota details: Applying under Sports, ECA, CW, Ward Quota, Kashmiri Migrant, or other special quotas, if eligible
• Document upload: Uploading scanned photograph, signature, certificates, and ID proof
• Fee payment: Paying the non-refundable registration fee to complete the process

Documents Required Before Starting

Keep the following ready as clear scanned copies (PDF/JPEG) before you begin, so you’re not scrambling mid-application.

Also read: DU SC/ST Quota Guide

Step-by-Step Registration Guide:

Step 1 – Visit the Official DU CSAS Portal

• What to do: Go to the official portal at admission.uod.ac.in (also linked from ugadmission.uod.ac.in). Do not use any third-party website claiming to offer “DU registration.”
• Why it’s important: Registering on an unofficial site can expose your personal data and CUET credentials to fraud.
• Common mistakes: Landing on outdated or fake portals via search ads or forwarded links.
• Pro tip: Bookmark the official portal directly and always type the URL yourself rather than clicking random links.

Step 2 – Register Using CUET Application Number

• What to do: Click “New Registration,” then enter your CUET UG 2026 Application Number and Date of Birth to begin. You’ll then set up a password and complete OTP verification via your registered mobile number and email.
• Why it’s important: Your CUET application number is the anchor for your entire CSAS profile — DU uses it to pull your exam and academic data.
• Common mistakes: Using a different email/mobile number than the one linked to CUET, which can cause OTP or verification issues.
• Pro tip: Use the same email ID and mobile number that you used for CUET registration to avoid login mismatches later.

Step 3 – Verify Auto-Fetched Details

• What to do: Once you log in, the system auto-fetches your name, date of birth, gender, and other basic details from your CUET application. Check every field carefully.
• Why it’s important: These details form the basis of your entire admission record — any discrepancy here can cause problems at document verification later.
• Common mistakes: Assuming auto-fetched data is always correct and skipping the review step.
• Pro tip: Keep your CUET admit card open in another tab to cross-check every auto-fetched value.

Step 4 – Fill Personal Information

• What to do: Enter details such as parents’/guardians’ names, nationality, gender, blood group, and contact information not already auto-fetched.
• Why it’s important: Parents’ names are frequently cross-checked against your Class 10 and Class 12 certificates during verification.
• Common mistakes: Spelling parents’ names differently from how they appear on your board certificates.
• Pro tip: Copy names exactly as printed on your Class 10 certificate — don’t “correct” spellings yourself.

Step 5 – Fill Address Details

• What to do: Enter your permanent and correspondence address, including state, district, city, and PIN code.
• Why it’s important: This address may be used for any physical communication and is sometimes referenced in category/domicile-related claims.
• Common mistakes: Leaving the correspondence address blank or entering an old address that’s no longer active.
• Pro tip: Double-check your PIN code — a wrong one is a common, easily avoidable data-entry slip.

Step 6 – Enter Class X Details

• What to do: Enter your Class 10 board name, roll number, year of passing, and marks/grades as printed on your certificate.
• Why it’s important: Class 10 records are treated as the primary proof of your date of birth throughout the admission process.
• Common mistakes: Typing marks or percentages incorrectly, or entering the wrong passing year.
• Pro tip: Keep your original Class 10 marksheet next to you and enter data exactly as printed, digit by digit.

Step 7 – Enter Class XII Details

• What to do: Enter your Class 12 board, roll number, subjects studied, and marks (or provisional details if results are awaited).
• Why it’s important: DU strictly enforces subject mapping — only subjects you actually studied and appeared for in Class 12 are considered valid for programme eligibility.
• Common mistakes: Selecting a subject you didn’t study, or mismatching your CUET test papers with your Class 12 subjects.
• Pro tip: Refer to the UG Bulletin of Information 2026-27 to confirm which subject combinations are valid for your intended programme before filling this section.

Step 8 – Fill Category Details

• What to do: Select your category (General/UR, SC, ST, OBC-NCL, EWS, PwBD) and upload the relevant certificate if you’re claiming a reservation benefit.
• Why it’s important: Your category affects your registration fee, eligibility relaxations, and seat allocation process.
• Common mistakes: Uploading a state OBC certificate instead of a Central List OBC-NCL certificate, or using an expired EWS/OBC-NCL certificate.
• Pro tip: Verify your certificate’s validity date and issuing authority before uploading — an expired certificate can lead to rejection of your category claim.

Step 9 – Fill Quota Details (Sports, ECA, CW, Ward, etc.)

• What to do: If applicable, select the supernumerary quota you wish to apply under — Sports, ECA (Extra-Curricular Activities), CW (Children/Widows of Defence Personnel), Ward Quota, Kashmiri Migrant, or others — and upload the supporting certificates.
• Why it’s important: These quotas offer additional seats beyond the regular merit list, but require separate documentation and, in most cases, an additional fee.
• Common mistakes: Applying under a quota without matching supporting proof, or missing the additional quota-specific fee payment.
• Pro tip: Only apply under quotas you can genuinely substantiate with valid certificates — unsupported claims can delay or jeopardise your entire application.

Also read: Delhi University Sports Quota Admission Guide

Step 10 – Upload Documents

• What to do: Upload your photograph, signature, Class 10 and 12 certificates, ID proof, and any category/quota certificates in the prescribed format and size.
• Why it’s important: This is the digital record DU uses for preliminary scrutiny before physical verification later.
• Common mistakes: Blurry scans, wrong file formats, oversized files, or documents with missing corners/seals.
• Pro tip: Use colour scans with good lighting, and rename files clearly (e.g., “Class10_Marksheet”) so you don’t upload the wrong document by mistake.

Step 11 – Preview Application

• What to do: Before final submission, use the “Preview” option to review every section of your application — personal details, academic records, category, quota, and uploaded documents.
• Why it’s important: In most years, Phase I basic details cannot be edited after final submission, except during a specific correction window.
• Common mistakes: Skimming through the preview quickly instead of checking each field carefully.
• Pro tip: Read the preview line by line — treat it as your last real chance to catch errors before they become harder to fix.

Step 12 – Pay Registration Fee

• What to do: Pay the applicable registration fee via debit card, credit card, net banking, or UPI. If you’ve opted for Sports/ECA or other paid quotas, pay those additional fees as well.
• Why it’s important: Your application is considered complete only after successful payment realisation — an unpaid form does not count as a valid registration.
• Common mistakes: Assuming the form is submitted once details are filled, without confirming that the payment went through.
• Pro tip: After paying, wait for the payment confirmation screen and check your registered email for a payment receipt before closing the browser.

Step 13 – Download Confirmation

• What to do: Once payment is confirmed, download and save your confirmation page/receipt for future reference.
• Why it’s important: This confirmation is your proof of successful Phase I registration and may be needed at various points during admission.
• Common mistakes: Not saving a copy, and later struggling to retrieve it if the portal has technical issues.
• Pro tip: Save a PDF copy on your device and store a backup on cloud storage or email it to yourself immediately.

Registration Fee (Category-wise)

All fees are non-refundable. Applying under both Sports and ECA quotas means paying ₹100 for each, separately. Always confirm the current fee structure on the official portal, as amounts can be revised each year.

File Upload Guidelines

Exact size limits (in KB/MB) are specified on the live CSAS portal and can change year to year — always check the current instructions on the upload screen itself before scanning your documents.

Common Errors During Registration

• Payment failed: Transaction shows failure or amount deducted but status not updated — wait, refresh the dashboard, and contact the helpdesk if the fee doesn’t reflect within a reasonable time before retrying payment.
• Name mismatch: Name differs between CUET application, Class 10 certificate, and Aadhaar — leads to verification delays later.
• Wrong category selected: Selecting a category you don’t hold valid certification for, or confusing state OBC with Central OBC-NCL.
• Invalid or expired certificate: Uploading an outdated EWS/OBC-NCL certificate that doesn’t meet the current year’s validity window.
• Blurred or unreadable documents: Poor scans that obscure seals, signatures, or key details, triggering rejection during scrutiny.

Frequently Asked Questions (FAQs)

Q. What is DU CSAS Phase I registration?

Ans: It’s the first stage of DU’s undergraduate admission process, where you create your profile, enter personal and academic details, upload documents, and pay the registration fee.

Q. Is CUET UG compulsory for DU CSAS registration?

Ans: Yes. CUET UG is the sole eligibility criterion for regular DU UG admission, and you need a valid CUET application number to register.

Q. Can I edit my details after submitting Phase I?

Ans: Generally only during a specific correction window opened by DU. Outside that window, most basic details cannot be changed.

Q. What happens if my Class 12 result is awaited?

Ans: Most years, DU allows registration with provisional details; you must update final marks and upload the passing certificate once available.

Q. Is the registration fee refundable?

Ans: No, the DU CSAS registration fee is non-refundable, regardless of the outcome of your application.

Q. How much is the DU CSAS registration fee?

Ans: It is typically ₹250 for General/OBC-NCL/EWS candidates and ₹100 for SC/ST/PwBD candidates, with additional fees for Sports/ECA quotas.

Q. Can I apply under more than one supernumerary quota?

Ans: Yes, but each quota (Sports, ECA, etc.) usually requires a separate additional fee and its own supporting certificate.

Q. What if my payment fails but money is deducted?

Ans: Wait for the payment status to update on your dashboard; if it doesn’t reflect after a reasonable time, contact the DU CSAS helpdesk before attempting payment again.

Q. Do I need to fill college preferences in Phase I?

Ans: No. College and programme preference filling happens in Phase II, after Phase I registration is complete.

Q. What documents are mandatory for everyone in Phase I?

Ans: Class 10 and 12 documents, photograph, signature, and a valid government ID are mandatory for all applicants, regardless of category.

Q. Is a category certificate compulsory?

Ans: Only if you’re claiming a reservation benefit under SC/ST/OBC-NCL/EWS/PwBD categories.

Q. Can I use my Aadhaar photo for the photograph upload?

Ans: It’s best to use a recent, clear photograph rather than an old ID photo, since it should be recognisable and portal-compliant.

Q. What if my name differs across documents?

Ans: You may need a notarised affidavit clarifying the name variation; try to correct it within the CSAS correction window if possible.

How do I know my registration is successfully completed? Your registration is complete only after successful fee payment, confirmed by a payment receipt and a downloadable confirmation page.

Q. Can I register on DU CSAS from a mobile phone?

Ans: Yes, the portal is generally mobile-accessible, but using a laptop or desktop is recommended for easier document uploads and form review.

Q. What should I do if I forget my CSAS password?

Ans: Use the “Forgot Password” option on the login page and follow the OTP-based reset process via your registered mobile number or email.

Q. Is there a deadline for Phase I registration?

Ans: Yes, DU announces a specific registration deadline each year — always check the current schedule on the official CSAS portal.

Conclusion

DU CSAS Phase I registration is more than just a form — it’s the foundation of your entire Delhi University admission journey. Getting each step right, from entering accurate personal details to uploading clear documents and confirming your fee payment, sets you up for a smoother Phase II and Phase III experience.

Take your time, keep every document ready in advance, and preview your application carefully before submitting. For the most accurate and current instructions, always refer to the official DU UG Bulletin of Information 2026-27 and the live CSAS portal at admission.uod.ac.in, since exact steps, fees, and file specifications can be updated by the university from year to year.