How to Unlock an SIM Card for Free

1. Contact the customer service department of your cellphone's network service provider and request a SIM unlock code for your phone. Your account must be in good standing for your cellphone carrier to provide you with a code. This code is usually free of charge.
2. Look for a free unlock code online. Websites such as Peters1, Hyfeno, Nokia Free, Unlock it Free and GSM liberty provide free unlock codes for a variety of cellphone models (see Resources).
3. Write the unlock code on a piece of paper when you are able to obtain it. To unlock your SIM card, follow the instructions provided for your specific phone model. Instructions vary by model.