How to Change Mobile Number on GST Portal? Complete 2026 Guide

The registered mobile number on the GST portal should be chosen carefully because every login, alert, and official update depends on it. On top of it, this number is your primary channel for receiving OTPs, reminders, and important GST notices. If this number becomes inactive or outdated, you may miss important updates or face login issues. That’s why it’s important to change your mobile number on the GST portal as soon as your contact details change.

Updating your mobile number avoids disruptions and keeps your GST compliance on track. This blog shows how to update your mobile number on the GST portal. It also covers verification and common issues, so your account stays secure and connected.

Role and Importance of Mobile Number on the GST Portal

The registered mobile number on the GST portal is the official contact number linked to the authorized signatory, aka you, the person officially allowed to manage the GST account. This number allows you to log in, file GST returns, update details, and receive OTPs. The portal uses it to verify identity during sensitive actions like profile updates or password resets, keeping the account secure from unauthorized access.

The GST portal (gst.gov.in) also classifies the mobile number as a non-core detail. This means changing the mobile number on the GST portal does not require approval from tax officers. Unlike core details like business name or address, updating your mobile number requires only OTP verification. This makes it easy to correct or update contact information without delays.

Why Updating Your Registered Mobile Number on GST Matters?

Your registered mobile number on the GST portal is more than just a contact detail. In fact, it plays a key role in keeping your account functional, secure, and compliant. 

It helps you:

• Receive OTPs instantly for logins, filings, and profile updates.
• Get alerts and reminders for deadlines, filings, and system updates.
• Stay informed about notices and compliance updates from GST.
• Verify your identity quickly when contacting GST support or resetting passwords.
• Avoid delays and penalties by keeping your number active.
• File GSTR-1 and GSTR-3B, and other returns easily with OTP verification.

Just as you can change your email ID on the GST portal to keep communication updated, maintaining an active mobile number ensures smooth GST operations.

Who Can Update GST Mobile Number?

To keep accounts secure, the portal allows only approved users to change the registered mobile number. These include:

• Primary Authorized Signatory: This person has full control of the GST account and can update the mobile number anytime from the profile section.
• Additional Authorized Signatory: This user can change the mobile number only when the primary signatory has given proper access rights.

If you do not have authorized access, ask the primary signatory to make the update or reach out to GST support for help.

What Do You Need Before Changing Your Mobile Number on the GST Portal?

Before you start the update process, keep a few details ready to avoid interruptions or failed verification.

• Active GSTIN: Make sure your GST Registration is active and not canceled or suspended.
• GST Login Credentials: You need your correct username and password to access the portal.
• Access to Registered Email ID: GST sends an OTP to your email for verification, so ensure it is active.
• New Mobile Number: The new number must be working and able to receive OTPs instantly.
• Access Rights of Authorized Signatory: Only a primary or permitted signatory can make this change.

Having these details in place helps you complete the update smoothly and without delays on the Goods and Services Tax Network (GSTN).

How to Change Mobile Number on the GST Portal?

The process to update your registered mobile number on the GST portal varies based on the role of the authorized signatory. If the signatory is also a promoter, partner, or proprietor, you can update the number directly from the profile section. If the signatory is not a promoter or partner, they must file a non-core amendment to change the mobile number.

Here’s the step-by-step process on how to change your mobile number on the GST portal:

Step 1: Log in to the GST Portal

Access the GST website and log in using your username, password, and captcha. 

Remember, only an authorized signatory can make profile changes.

Step 2: Identify the Role of the Authorized Signatory

Before proceeding, check whether the person whose mobile number you want to update is:

• A Promoter / Partner / Proprietor, or
• An Authorized Signatory who is not a promoter or partner

The next steps depend on this role.

Step 3: If the Authorized Signatory is Also a Promoter / Partner

If the person is already listed as a promoter or partner in the GST registration:

1. Go to My Profile from the dashboard.
2. Click on Authorized Signatory.
3. Select the relevant name and click Edit.
4. Enter the new mobile number carefully.

Since this is treated as a non-core detail update, no officer approval is required.

Step 4: If the Authorized Signatory is NOT a Promoter / Partner

If the person is only listed as an authorized signatory (for example, an employee or representative):

1. Go to Services → Registration → Amendment of Registration (Non-Core Fields).
2. Open the Authorized Signatory tab.
3. Select the signatory and click Edit.
4. Enter the new mobile number.
5. Submit the amendment application.

The portal will generate an Application Reference Number (ARN).

You generally do not need officer approval, but ensure the amendment is submitted correctly.

Step 5: Complete OTP Verification

In both cases, the portal will send:

• An OTP to the new mobile number
• An OTP to the registered email ID

Enter both OTPs to verify the change.

Step 6: Save and Confirm

Click Save/Submit to complete the process.

• If updated through the profile (Promoter/Partner case), the number becomes active immediately.
• If updated through amendment (Non-Promoter case), the change reflects after successful submission.

Mobile Number Update: Promoter/Partner vs Non-Promoter Signatory

The table below shows how the mobile number update process differs based on whether the authorized signatory is also a promoter/partner or not.

Criteria	Authorized Signatory is Promoter/Partner	Authorized Signatory is NOT Promoter/Partner
Where to Update	My Profile → Authorized Signatory	Services → Registration → Amendment (Non-Core Fields)
Amendment Required	No	Yes
ARN Generated	No	Yes
Officer Approval	Not required	Usually not required (non-core change)
Processing Time	Immediate after OTP verification	Immediately after OTP verification
OTP Verification	Required (Mobile + Email)	Required (Mobile + Email)

This distinction helps you choose the correct update method and avoid unnecessary delays while changing your GST-registered mobile number.

How to Check if the Mobile Number Update on the GST Portal Was Successful?

After updating your mobile number, you can confirm the change by:

• Logging out and signing back in to refresh your account.
• Visiting My Profile → Authorized Signatory to view the registered contact details.
• Verifying that your new mobile number is listed and active.
• Initiating an action that triggers an OTP to ensure the new number receives messages correctly.

This quick check ensures your GST account is fully updated and you continue receiving all alerts and notifications.

How Long Does it Take to Update the Mobile Number on the GST Portal?

After completing the process, you may want to know how long the new mobile number takes to update on your GST account.

In most cases, the update happens as soon as you submit the OTPs and see the confirmation message. Your new number starts working right away for logins, alerts, and notifications.

In rare situations, it may take a few hours due to heavy digital traffic or technical hiccups. Just give it a few hours, and the update should reflect automatically on the GST portal.

Common Issues While Updating Mobile Number on GST Portal

The process of changing the mobile number on the GST portal is easy, but small issues can pop up along the way. The good news is that most problems have simple fixes.

Here are the most common issues taxpayers face and how you can fix them:

• OTP not received: Network delays, busy servers, or email filters can cause this. Wait a minute, request the OTP again, and check your spam folder.
• Email inaccessible: GST sends a verification OTP to your email. If you no longer use it, the primary signatory or GST support must help.
• Not logged in as an authorized signatory: Only approved users can make changes. Switch to the correct account if you see permission errors.
• Portal errors or logouts: Heavy traffic can slow the system. Logging in again, clearing the browser cache, or trying again after some time usually fixes this.
• Number already linked: In rare cases, the portal may restrict numbers already heavily linked to multiple accounts. Use a unique number to avoid this issue.

If the problem continues, contact the Goods and Services Tax Network helpdesk at 1800‑103‑4786 (toll-free) for quick support. 

Struggling with OTP delays, access problems, or portal errors? Let RegisterKaro’s experienced team guide you through every step of GST updates, from mobile number changes to verification. We make the process quick, accurate, and seamless, so you never miss important alerts or deadlines. Contact us today!

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