MCA
Form ADT-1 Auditor Appointment 2026: DSC Rules, Deadline & Attachments
Published October 21, 2026 · By DSCKart
Companies must inform the Registrar of Companies when an auditor is appointed. The form is filed on the MCA portal and signed digitally, so a valid, registered Class 3 DSC is needed.
What is Form ADT-1?
Form ADT-1 is the form a company files with the Registrar of Companies to notify the appointment of an auditor under Section 139 of the Companies Act, 2013.
It is filed for first auditors, for appointments made at an AGM, and for reappointments.
What is the deadline for filing ADT-1?
Generally within 15 days of the meeting at which the auditor is appointed; the company also has to inform the auditor of the appointment.
For first auditors appointed by the Board, the Board appoints within 30 days of incorporation. Confirm dates on the MCA portal, as these can change.
Does ADT-1 need a DSC?
Yes. It is signed digitally by a director or other authorised signatory with a Class 3 DSC registered on the MCA portal.
Class 2 is no longer issued, and new certificates and renewals use FIPS 140-3 tokens. See the DSC for MCA page for what MCA21 requires. The auditor does not sign ADT-1 itself; the auditor gives a written consent and eligibility certificate that are attached.
What attachments does ADT-1 need?
The form is filed with the auditor's documents and the resolution that authorised the appointment.
- The auditor's written consent and eligibility certificate under Section 141.
- The appointment resolution or board/shareholder resolution as applicable.
- The appointment or intimation letter as required by the form.
Check the live form on the MCA portal for the exact attachments.
What happens if ADT-1 is filed late?
Late filing attracts additional fees under the MCA fee rules and may attract penalty for the company and officers in default.
Check the current fee schedule on the MCA portal for the amounts that apply to your filing.
Checklist before you file
Gather the auditor's documents first, then confirm the signer's DSC is valid and registered before you start the form.
- Confirm the auditor's consent and eligibility certificate are in hand.
- Check the signer's DSC expiry — see how to check DSC validity.
- Make sure the DSC is registered on the MCA portal for that signer.
- File, sign, and pay the fee shown on the portal.
- Keep the SRN and acknowledgement for your records.
Common errors that block ADT-1
An expired or unregistered DSC, a token the signing utility cannot detect, or a signer whose details do not match the portal are the usual blockers.
- Expired DSC discovered at the last step — renew early.
- Token not detected or emSigner not running — see common DSC errors and fixes.
- Signer details on the form do not match the DSC registered on the portal.
Related MCA guides
See AOC-4 & MGT-7 filing, MSME Form 1, DIR-3 KYC and LLP Form 8.
Frequently Asked Questions
What is Form ADT-1 used for?
Notifying the Registrar of Companies about the appointment of an auditor — a first auditor, an appointment made at an AGM, or a reappointment — under Section 139 of the Companies Act, 2013.
What is the due date for ADT-1?
Generally within 15 days of the meeting in which the auditor is appointed. Confirm the current position on the MCA portal.
Does ADT-1 need a DSC?
Yes. The form is signed with the Class 3 DSC of a director or other authorised signatory registered on the MCA portal.
Who files ADT-1, the company or the auditor?
The company files it. The auditor provides a written consent and an eligibility certificate, which are attached to the form.
Do LLPs file ADT-1?
No. ADT-1 is a Companies Act form, so LLPs do not file it.
What if my DSC has expired?
An expired DSC blocks signing at the final step. Renew it, register the new certificate on the MCA portal, and then file.
Need a valid DSC before you file ADT-1?
Get or renew a Class 3 DSC for the director who will sign, and file without last-minute errors.
General guidance only. Confirm due dates, fees, penalties and form fields on the MCA portal or with a professional.