How to upgrade BSNL 3G to 4G Sim Card



BSNL has started 4G VoLTE Services in some part of India. The state-owned company initially launched 4G VoLTE Services for pilot testing in Kerala. At present, BSNL 4G VoLTE services have started in few locations in different states like Kerala, Gujarat, Maharashtra, Jharkhand, Karnataka, Telangana, Andhra Pradesh and Chattisgarh. If you are a BSNL customer, you should know how to upgrade BSNL 3G to 4G Sim Card.

I will explain different ways to help you upgrade your BSNL 3G Sim Card to 4G Sim.

How to upgrade BSNL 3G to 4G SIM Card by SMS

BSNL has simplified the process of upgrading your SIM from 3G to 4G to make it convenient for their customers. You can now upgrade your SIM to 4G simply by sending SMS. The only thing you should ensure before using this method is to check whether your KYC (Know Your Customer) process is complete for your BSNL account. To upgrade your SIM from 3G to 4G, you should first complete the KYC process. Otherwise, your request for upgrade will not be accepted by BSNL.

Now, let’s see how the SMS method works.

  1. Check whether 4G VoLTE Services are provided in your area by BSNL.
  2. Check whether your SIM is 2G or 3G or 4G. Most of the SIM Cards issued by the telecom provides are 4G SIMs only. So, if you already have 4G SIM, you might not need a new SIM. You can upgrade with your existing 4G SIM only.
  3. If you don’t have 4G SIM Card, you should buy the same through SIM-Swap from nearest BSNL Centre or BSNL Channel Partner (Franchisee). Normally, the cost of 4G SIM Card is Rs. 20/- only. If there is any BSNL Mela event running in your area, you can get the SIM Card free of cost from such event as part of their promotional activity.
  4. After swapping your 2G/3G SIM Card to 4G SIM Card, you have to start the process of activating your 4G SIM using the SMS method.
  5. Open your Messaging App
  6. Type in the Message in the following format: RE4G <last 6 digits of the new SIM Card Number> <Circle Code>. I will show you with an example for better clarity. Assume that you live in Kerala and you have received a new 4G SIM Card with 19-digit number 1234567890123456789. To activate 4G Services on this SIM, you should send SMS with text “RE4G 456789 KL” where RE4G is the fixed text, 456789 is the last six digits of the new 4G SIM Card and KL is the Circle Code for Kerala.
  7. You should send the SMS in the above format to 53734 using your existing BSNL Number with old SIM.
  8. You will receive a message “Dear Customer. This connection will stop working within 15 mins of SMS RE4G < space > YES to 53734. Please send ‘YES’ only if you have received new SIM card: 1234567890123456789 and it is with you”.
  9. Verify the SIM Card Number received in the text message with your new 4G SIM Card to check if it is matching.
  10. After receiving the above message, send an SMS with text “RE4G YES” to 53734.
  11. You will receive a new message from BSNL “Dear Customer, your request for 4G SIM swap registered successfully. Please check after 1 hour to get the services on new SIM issued”.
  12. After some time, you will receive a new message from BSNL before disconnection of your old SIM – “Dear Customer, your request for SIM swap has been registered in Sancharsoft with …… (CSC or franchise details from where you got the new SIM). If request is not submitted by you. Pls report to them immediately to stop it.”
  13. Now, wait for the network signal on your phone with old SIM to disconnect automatically.
  14. After the network signal disappears in your phone with old SIM, replace the same with new 4G SIM Card and switch on the phone.
  15. Your have successfully activated BSNL 4G VoLTE Services on your phone.

Upgrading to BSNL 4G by visiting CSC / Channel Partner

The process is as follows:

  1. Visit your nearest BSNL CSC/Channel Partner.
  2. You have to complete the required formalities for issue of new 4G VoLTE SIM Card. If KYC is not done, KYC Process should also be completed. Carry your Proof of Address, Proof of Identity & Aadhaar Card along with you.
  3. After completing all the formalities, you will get the new 4G SIM.
  4. BSNL will send you a Pre-formatted message in your current BSNL Number for which you requested the new 4G SIM.
  5. You have to send this Preformatted message (Message format would be like ” RE4G 1234567890123456789 50″ where RE4G is fixed text, 1234567890123456789 is 19-digit SIM Number and 50 is Circle Code for Kerala) to 53734.
  6. BSNL will send you a confirmation SMS regarding your request.
  7. BSNL will activate the 4G SIM in short time.

I hope the above guide on how to upgrade BSNL 3G to 4G SIM Card helps you in replacing your old 2G/3G SIM with the new 4G SIM.

If you have any doubt regarding the process, please feel free to share in the comments section.

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28 thoughts on “How to upgrade BSNL 3G to 4G Sim Card”

  1. Sent the first message Reg4g 123456 gl but the SIM # for new SIM was incorrect. Still old SIM stopped working.

    However did not send the confirmation yes message.

    Will my sim not work now??

  2. Please clarify whether BSNL 4G SIM IS AVAILABLE IN CHENNAI (SELAIYUR). Should I have to apply for New 4G Sim in writing?, and Code for Tamilnadu.

    • BSNL 4G Service is available in Chennai. You will have to visit the nearest CSC in Chennai and submit the Application Form for New SIM along with KYC documents (Proof of Address & Proof of Identity).

  3. I have converted my bsnl 3G sim into 4G sim . The sim got activited and all features like calling and internet is working but when I send SMS to anyone it shows “SMS not sent” …. Plz help me

    • If your 4G SIM was activated recently, you might have to wait 24 hours for the SMS service to activate.

      If 24 hours have passed since 4G SIM activation, please check if the Message Center Number in your phone is entered correctly.

      If you are not able to resolve the problem yourself, contact BSNL Customer Care & explain your problem.

  4. i have bough 4 g sim in chennai in jan now i am in manglore which is a bsnl 4g area . @g tower is geting connected but 4g tower is not geting conected . i treid contacing customer care telling such problem they further guided me teling to sent the smsRE4g….. . reply message came as sim is not a valid 4g sim . (apparently when bought as new it was 4g sim).now again contacting them telling the situation they tel ur sim is 3g and not 4g.Any solution to other than going to sim centre which is under curfew now?

    • You are telling that you sent the SMS for activation of 4G and the reply was that your SIM is not valid 4G Sim. In that case, you will have to replace your SIM through SIM Swap. You will have to upgrade your SIM to 4G and then, you can avail 4G services. You will have to wait till completion of this lock-down as there is no way to replace your SIM as all offices & stores are closed.

  5. sir Iam little confused for my last 6 digit code of my sim card where do I find it???? Eg:1234567890123456789 is my sim card code and 456789 is my last 6 digit code?????

  6. Yeh I have the code on the SIM that is 19 digit code and where I find the last 6 digit code???? In the beginning 6 number or the ending 6 number??

  7. Sir, I’ve a bihar bsnl sim, it’s 3G or 2G, I don’t know. How to know that? Also I want to upgrade it to 4G sim, but problem is I stay in Bengal now, not bihar. ..I don’t want to change it or port it. My mobile set is 4G. can I upgrade it to 4G from Bengal no?, kindly reply &solve my problem, I’m in tension


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