How to Subscribe to MTN Always-On Data Subscribing is easy! You can activate your plan via SMS, USSD code, or the MyMTN App. Here’s how to do it using USSD codes: For 45GB at 6000 Naira: Dial *312*163# or *312*1*5#, then follow these steps: Ensure you have at least 6000 Naira airtime in your balance. Dial the code. Choose whether you want auto-renewal or not. Confirm and pay. 1.5GB will be credited to your account immediately! For everyday you get 1.5GB any unused data will be rollover to the next day.. For 15GB at 3000 Naira: Dial *312*162# or *312*1*5*1#, then follow the same process. You will receive 500MB instantly.