Most people have been trying to understand how the 4G Sim card Upgrade works... Here is a brief explanation: If your Sim card is the former 3G Sim card it will not be able to activate 4G in your phone even if your phone is a 4G phone. WHAT SHOULD YOU DO? What you should do is to go to your network provider's office close to you and request for sim upgrade. REQUIREMENTS Sim Card Upgrade is simply a sim swap that is carried out on your line so you can be given another new Sim Card (4G Sim Card). Therefore just like going for welcome back, you need to go with photocopy (compulsory) and original (incase it will be required) of any of VOTER'S CARD, NATIONAL ID, DRIVERS LICENSE OR INTERNATIONAL PASSPORT. YOU WILL ALSO PAY SAME AMOUNT AS PAID FOR WELCOME BACK BY YOUR NETWORK PROVIDER. NOTE: MAKE SURE YOU BACK UP YOUR OLD SIM CARD CONTACTS ON GOOGLE USING YOUR GMAIL OR ANYWHERE ELSE BECAUSE YOUR OLD SIM WILL BE COLLECTED OR DESTROYED. THANK YOU!