Hi @Simrenkaur,
Welcome to the EE Community
Is this an existing SIM that has suddenly stopped working or is it a new SIM that you have just gotten that is not working?
If you have not already make sure to restart your phone. Are you getting any kind of error message on the phone?
Our customer service team are available 8am to 9pm on weekdays, 8am to 8pm on weekends if you do wish to get in touch for help with your SIM.
Alex
