Unwanted calls can disrupt your day. Fortunately, you can block a number from calling you on MTN, Glo, Airtel, or 9mobile networks using either your phone's built-in features or network-level USSD codes. Blocked calls go to voicemail, and blocked text messages land in the undelivered folder. This guide explains the methods for each network and device type.
Network-Level Blocking with USSD Codes
Carrier-level blocking stops the number regardless of which phone you use. However, these codes typically block all incoming calls rather than a single contact. For MTN Nigeria, dial *35*0000*Nigerian phone number# (e.g., *35*0000*08123456789#) to block a specific number. To unblock all, dial *35*0000#. For international numbers, use *351*international number#. A small fee may apply. This block persists even if you change your phone or swap SIM cards. Note that MTN Uganda uses a different code: dial 21190# to block all incoming calls, and ##002# to restore.
For Glo, the standard GSM code for barring incoming calls is *35*0000#. To remove barring, dial #35*0000#. Glo indicates that barring affects all incoming calls, so use your phone's blocklist for a specific contact. Airtel Nigeria activates call barring using a personal PIN 2; contact customer care for assistance. Alternatively, use Airtel's Do-Not-Disturb service by sending STOP to 2442 for promotional messages. For 9mobile, dial *35*0000# to bar incoming calls and #35*0000# to deactivate. If your barring PIN has changed, use the current one.
Blocking Numbers on Android
Android devices offer several ways to block a specific number. Use the Phone app: open the Phone app, tap the three-dot menu, go to Settings > Block numbers, tap the plus sign, and add the number from your contacts or call log. Alternatively, from your contact list, select a contact, tap the three-dot menu, and choose Block. To block via the Messages app, open the conversation, tap the More icon, and select Block number. These methods work across all networks.
Blocking Numbers on iOS
On an iPhone, open the Recents list, tap the information icon (i) next to the number, scroll down, and tap Block this Caller. To block a contact, go to Settings > Phone > Call Blocking & Identification, then select the contact to block. This permanently stops calls and texts from that number until you remove the block.
Blocking Numbers on Windows Phone and Button Phones
For Windows phones, open the Phone app, press and hold the number you want to block, and select Block. You can also enable call and SMS filtering in Settings. For button phones (feature phones), the process varies. Look for a Blacklist or Reject List option in Contacts or Call Log. If unavailable, use the network's call-barring code as a workaround, though it will block all incoming calls.
Using Third-Party Apps and Do Not Disturb
If your phone lacks robust blocking features, consider third-party apps like Truecaller, Mr. Number, Calls Blacklist, or Should I Answer?. These apps allow granular control. To stop calls without blocking, enable Do Not Disturb mode in your phone settings and choose to allow no calls. Alternatively, use flight mode or voicemail forwarding.
Permanent Blocking and SIM Card Suspension
Blocking via phone settings is permanent until you manually remove the number. For a block that survives a lost phone, pair it with network-level call barring. Occasionally review your blocklist, as phones rarely notify you when it becomes long. If your MTN SIM is lost or stolen, suspend it through the MyMTN app or by calling 180 from another line. This stops all activity on your line, not just a single caller.
Understanding the difference between per-contact blocking and call barring is crucial. Use your phone's blocklist for a specific person and network codes only when you want to stop all incoming calls.
