How to test SIM registration and status?

What are good commands for testing SIM card status and registration issues?

Today, I was experimenting with how to recognize SIM card problems. I took 3 cards that are known to be bad when tested in other hardware, and expected to find some clear results. I didn’t, but I think I just need some guidance for what commands to be using.

The command that made the most sense was:

AT+CEREG?

I received 3 different responses:

  • 0,3
  • 2,1
  • 2,4

The first is “denied” which is fairly straightforward. The 2nd suggested it is successfully registered, but it would not provide an IP address and didn’t actually function. The 3rd behaved like the 2nd, but had the “4” suggesting “other” for a registration status. They also showed servingcell info, and +QNWINFO information even though I thought they shouldn’t.

What other commands are helpful for tracking or understanding card issues. I want to be able to find when there is a card problem so I know when to replace a card and when to troubleshoot modem issues / configurations.

Thank you, Chris

Dear Uberdome,
Thanks for your inquiry in Quectel forum.
About your issue, it is better to use AT+CREG? and AT+CEREG? to check it.


image
Normally, we just need to care about the second parameter of the return value, the following is the explanation about the return value. Only the second parameters return 1 or 3, it just can said that the module already register on local network or roaming network. Thanks!

Testing further, I found these results on 2x of the cards:

AT+CEREG?                 
+CEREG: 2,4
OK

AT+CREG? 
+CREG: 2,1,"1B52","7DAC58D",2
OK

This looks like they are only connecting to 3G connections. They are configured, however, to only search LTE connections here:

AT+QCFG="NWSCANMODE",3	

What sort of behavior gives the result “unknown” for registration status?

Thank you, Chris

Dear Chris,
Could you help to provide more information to us, then we can help confirm the issue. Thanks!
Have you change another SIM card to have a try ? If you do not fix NWSCANMODE to LTE only, whether it is still have such results ? And how about the LTE network signal, could you double check it ? Thanks!

Hello,
According to ATI, I have BC66NBR01A10. And it makes answer for command AT+CREG? +CREG: 0,5.
But in manual Quectel_BC66BC66-NA_AT_Commands_Manual_V2.2.pdf is no such command. Where this command is described for my device?

hi,
If you are using BC66, you are advised to use “AT+CEREG” to check the registered network status.
You can also perform the following commands to check network or signal conditions:

AT+CSQ
AT+CESQ
AT+QENG=0
AT+COPS?
AT+CGATT?

Today, I was experimenting with how to recognize SIM card problems. I took 3 cards that are known to be bad when tested in other hardware, and expected to find some clear results. I didn’t, but I think I just need some guidance for what commands to be using.

Which type of model do you use?

Testing your SIM registration and checking its status can vary depending on the telecom provider, but generally follows similar steps. Here’s how you can test your SIM registration and status:

1. Check via USSD Code (for some providers)

  • Some telecom operators offer a USSD code that allows users to check their SIM registration status. Dial the specific USSD code provided by your network (e.g., *123#, *121#, or similar) and follow the instructions. You may find an option to verify your registration status.

2. Check via SMS

  • Some telecom providers also allow you to send an SMS to a designated number to check your registration status. For example, send an SMS with the keyword “REG STATUS” or a similar command to the network’s inquiry number.

3. Use Provider’s Official App or Website

  • Visit your telecom provider’s website or mobile app (such as Smart, Globe, TNT, etc.). They often have a “SIM Registration” or “Check Status” option in their services section. Simply log in with your mobile number, and you’ll be able to see your SIM registration status.

4. Customer Service Hotline

  • You can also call your provider’s customer service hotline and request information about your SIM registration. The representative will verify your identity and give you an update on your registration status.

5. Visit an Authorized Store or Kiosk

  • If you’re unsure or have trouble accessing the digital tools, you can visit a nearby service center, kiosk, or authorized retailer. The staff will be able to help you check your registration status and guide you through the process if you haven’t registered yet.

6. Notifications

  • Some telecom providers may send SMS notifications regarding the status of your SIM registration, especially if the deadline is approaching or your SIM needs to be registered.

Ensuring your SIM is registered helps prevent service disruption and ensures compliance with government regulations.

To check your SIM registration status, you can use a USSD code provided by your telecom provider, like *123# or *121#. Simply dial the code and follow the prompts. Alternatively, you can send an SMS with a keyword like “REG STATUS” to your network’s inquiry number, or log in to your provider’s app or website to verify your SIM registration.

If you’re unable to use these options, you can call your provider’s customer service hotline for assistance. You can also visit an authorized store or service center to get in-person help with checking your registration status and ensuring compliance with regulations.

To check your SIM registration status, there are several easy methods available like dialing a USSD code, sending an SMS, or using your provider’s app. If these options don’t work, you can always contact customer service or visit a store for help. For Globe SIM users, globe sim registration online can also be done by visiting their official website, where you can verify or update your registration details conveniently.

The process for checking SIM registration status and Test of Globe SIM widely done by Philippines People at globe online portal after registration.