How do I add a phone number to the SIM900? Can I add a phone number to the SIM900? Assuming I can, would I send the phone number through the AT Commands or the actual SIM card? I don't know how to write to a SIM card without another phone, so I am lost on how to write it standalone. The purpose of this is that I want to add my phone number to another device that uses Arduino and an SIM900 breakout. It is a project that could use that "phone" to receive calls and SMS and etc.

  • \$\begingroup\$ A phone doesn't have a number without a SIM card. \$\endgroup\$
    – Matt Young
    Feb 19, 2015 at 3:11
  • \$\begingroup\$ As Matt says, take the SIM out of your phone to test the SIM900. You can get SIM's for pay-as-you-go phones anywhere or get bulk SIMS from a service provider. I get them from T-Mobile for one customer. Verizon doesn't use SIMS and AT&T is impossible to deal with. T-Mobile will send a rep out to see what you need. \$\endgroup\$ Feb 19, 2015 at 6:02
  • \$\begingroup\$ Yes well then how do I add the phone number to the new SIM? Do I just put it into my phone and then setup the number as before? Then once it is in do I transfer it to the SIM900? \$\endgroup\$
    – Jdude2345
    Feb 19, 2015 at 14:10

1 Answer 1


You don't write a phone number to the SIM900.

Your cellular service provider writes the phone number, along with other account information, to a SIM card. You connect the SIM card to the device.

You will need a separate phone number for the SIM900 - unless you want to pull the sim card out of your phone every time you want to use it.

Even if you could program a new SIM card to have exactly the same information as the one in your phone, your provider would detect that and be very unhappy with you.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.