You can change the mobile number and email address linked to an existing GST registration through Services > Registration > Amendment of Registration Non-Core Fields. Update the appropriate person’s record, complete the verification prompts shown on the portal, and submit the amendment. The “5 minutes” in the original title is not a guaranteed completion time: OTP delivery and account-specific steps can affect how long it takes.
Before you start
- Have your GST Portal login credentials ready.
- Know whether the contact details belong to the authorized signatory or to a promoter/partner who is also the primary authorized signatory.
- Be prepared to complete the OTP verification and filing authentication the portal requests. The GST Portal Welcome Kit describes DSC or EVC authentication as applicable: GST Portal Welcome Kit.
Change the mobile number or email on the GST Portal
- Log in to the GST Portal using your valid credentials.
- Go to Services > Registration > Amendment of Registration Non-Core Fields. The GST Portal manual identifies this route for non-core amendments: Amendment of Non-Core Fields.
- Open the tab for the person whose contact details need to change: Authorized Signatory or Promoter/Partner.
- Edit the mobile number and email address as needed, save the record, and complete the OTP verification displayed by the portal.
- Complete the verification declaration, select the authorized signatory, enter the place, and submit using the authentication method available to you, such as DSC or EVC.
- Save the acknowledgment or ARN for your records. The Welcome Kit says the acknowledgment is sent within 15 minutes after submission; that is an acknowledgment timing, not an estimate of how long the entire amendment takes.
If the promoter or partner is also the primary authorized signatory
Use the Promoter/Partner tab to edit that person’s mobile number and email. The GST Portal manual describes separate OTPs sent to the new mobile number and email in this case. Once saved, the updated details are reflected in the Authorized Signatory tab when both records refer to the same person; then submit the application. See the GST Portal FAQ on amendment of enrolment applications.
What verification should you expect?
The OTP flow can differ according to the record being amended. For an authorized-signatory update, the manual describes entering the OTP prompted by the portal, and says the common OTP sent to the updated email and mobile is valid for 10 minutes. For the promoter/partner case described above, it specifies separate OTPs. Follow the current on-screen instructions rather than assuming every account receives the same OTP format.
What happens after you submit?
This is an amendment to non-core registration fields. The GST Portal manual says non-core amendments do not require tax-official approval and are automatically updated in the GST database after successful filing: GST Portal manual: Amendment of Non-Core Fields.
Recommended Free Tools
#1 Best Overall
- Profitability calculations; cash flow function Calculates NPV and IRR for uneven cash flows
- Time-value-of-money and Amortization keys solve problems including: pension calculations, loans, mortgages, etc.
- Ideal calculator for students, managers and statisticians
- Built-in functionality : List-based one- and two-variable statistics with four regression options: linear, logarithmic, exponential and power
- The BA II Plus calculator is approved for use on the following professional exams: Chartered Financial Analyst exam. GARP Financial Risk Manager (FRM) exam. Certified Management Accountants exam
If you cannot complete OTP verification
The official material cited here does not specify a recovery route for someone who cannot access the old or new contact channel needed for verification. Do not assume there is an OTP bypass. Check current GST Portal support instructions or consult a qualified tax professional for help with your account.
Quick Recap
Best Value
- Two-way Power Desk Calculator: Use solar power or battery power,In the case of sunlight or light, it can also be used without battery (Provide 2 AA batteries, only 1 needed).
- Optimized for Desk Use: The angled display offers a better viewing angle, especially when placed on a flat surface.
- Ergonomic Screen Tilt: Reduces neck strain with a user-friendly viewing angle, naturally aligning with your line of sight for a more comfortable experience.
- 10-Key Calculator with Large Buttons: Easy-to-use design follows computer keyboard layout.
- Desktop Basic Office Calculator:Perfect for daily use in offices, businesses, schools, retail stores, shopping centers, and home offices.
Rank #4
- Two-way Power Desk Calculator: Use solar power or battery power,In the case of sunlight or light, it can also be used without battery (Provide 2 AA batteries, only 1 needed).
- Optimized for Desk Use: The angled display offers a better viewing angle, especially when placed on a flat surface.
- Ergonomic Screen Tilt: Reduces neck strain with a user-friendly viewing angle, naturally aligning with your line of sight for a more comfortable experience.
- 10-Key Calculator with Large Buttons: Easy-to-use design follows computer keyboard layout.
- Desktop Basic Office Calculator:Perfect for daily use in offices, businesses, schools, retail stores, shopping centers, and home offices.
Rank #3
- [GIANT CLEAR DISPLAY] - Large 5 Inch and clear 12-digit display screen allows for easy readability and usage, relieving any strain on your eyes.
- [USEFUL FUNCTIONS] - Grand Total/Markup/Memory Clear and Recall/Memory Add/Subtract Function keys help with basic and complex calculations.
- [LARGE EASY TO USE DESIGN] - Large buttons and Easy To Read Display make it simple and convenient to use, whether at home or the office.
- [EFFICIENT ENERGY SOURCE] - Dual solar energy and battery power sources give this product a long-lasting battery life, so you never have to worry about running out of power. Also has Auto Power-Off. The calculator will turn itself off after about 6 minutes of being idle.
- [HIGHLY DURABLE] - Well built and durable plastic keys allow for constant use without any wear and tear, giving you the feel of quality.
Rank #2
- PROFESSIONAL FINANCIAL CALCULATOR : Built-in TVM, IRR, NPV. Engineered for business analysts, real estate investors, accountants, and finance students.
- ADVANCED CASH FLOW & AMORTIZATION : Execute time value of money, break-even analysis, depreciation schedules, and bond pricing. Trusted for professional exam prep", MBA coursework, and banking certifications.
- CATIGA CF-300 : Flip-open hard case with a snap-close design for a secure fit. Compact and portable: designed for daily professional use in office, classroom, or on-site.
- ALL-IN-ONE FOR PROFESSIONALS : From NPV/IRR for real estate analysis to statistical calculations for business analysts. Handles probability, linear regression, and complex financial formulas.
- MORTGAGE, LOAN & INVESTMENT CALCULATOR : Covers bond pricing, loan amortization, investment analysis, and exam-level computations. Your go-to accounting calculator, business calculator, and real estate calculator in one device.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.
