Last verified: July 20, 2026
Quick Answer
Here is how to check my MTN number, and anyone else’s on the SIM in front of you: dial *123*888# from the MTN SIM itself, or dial *123# and work through the menu. Press call, and your 10-digit number pops up on screen within seconds.
The service is standard across MTN South Africa for active prepaid, top-up, and contract SIMs. If the network is slow to answer, you can also surface your number by sending a free “Please Call Me” (*121*mobile number#) to a phone next to you, or by opening the zero-rated MTN Mobile App.
What the Service Is and Who Can Use It
The MTN own-number check queries the network directly and returns the mobile station international subscriber directory number (MSISDN) tied to the physical SIM or eSIM in your handset. It is the same number other people see when you call them.
Eligible Users and Requirements
- Prepaid Subscribers: Any active prepaid SIM registered under RICA.
- Contract and Hybrid/Top-Up Users: Active postpaid account SIMs.
- Handset Compatibility: Every device, from basic feature phones through 3G/4G/5G Android handsets and iPhones.
- Network Status: The phone needs live signal on the MTN South Africa network.
Exclusions and Limitations
- Un-RICA’d or deactivated SIMs: A SIM that never completed RICA registration, or that expired and was recycled after long inactivity, cannot open a USSD session at all.
- Data-only routers and modems: Without a phone dialler they cannot run USSD codes. Use the router’s web admin page, or move the SIM into a phone.
How to Check the Mobile Number
Before You Start
- Check the SIM is seated: Make sure the MTN SIM sits properly in the tray.
- Dual-SIM phones: Know which slot holds the MTN SIM, 1 or 2, so you dial out on the right line.
- Signal strength: At least one bar.
Verified Step-by-Step Process
- Open the Phone / Dialer app.
- Key in
*123*888#. - Tap Call / Dial. On a dual-SIM phone, pick the MTN SIM line.
- Wait a few seconds for the USSD session to run.
- Read your 10-digit number off the pop-up.
Alternative direct code: You can also dial
*135#or*123#and navigate the interactive main menu to reach your account details.
Confirmation or Expected Result
On success, a flash menu overlay or dialog box appears on screen:
Screen Display:
"Your phone number is: 083 XXX XXXX"(or starting 071, 073, 078, 081, and so on).
- Format: The number appears in the standard South African 10-digit national format (
0XX XXX XXXX) or the international format (+27XX XXX XXXX). - Storage: USSD pop-ups are temporary. Screenshot it or write it down before you dismiss the box, because there is nothing to scroll back to.
Fees, Limits, Eligibility, and Processing Times
| Feature | Details |
| Service Cost | Free (R0.00). Querying your number deducts no airtime and no data. |
| Airtime Required | R0.00 balance required (works with zero balance). |
| Daily Request Limits | Unlimited requests. |
| Processing Time | Near-instant (typically 2 to 5 seconds). |
| Roaming Availability | Available on the home network; international roaming depends on the local partner’s USSD support. |
Common Problems and Troubleshooting
Code, Session, SIM, or Account Errors
- “Connection Problem or MMI Code Invalid”:
- Cause: Network congestion, weak coverage, or the wrong SIM slot on a dual-SIM phone.
- Solution: Turn Airplane Mode on for 5 seconds, turn it off, select the MTN SIM line, and redial
*123*888#.
- Blank screen or timed-out session:
- Cause: Cell tower delay during the USSD handshake.
- Solution: Redial, or restart the phone.
- “SIM Not Provisioned” or no network service:
- Cause: A brand-new SIM not yet linked to a RICA profile, or one blocked after long inactivity.
- Solution: Complete RICA registration with an official MTN agent or store.
Alternative Quick Methods if USSD Fails
- Send a free “Please Call Me”: Dial
*121*0XXXXXXXXX#using a friend’s number. The SMS they get shows your number as the sender. - Call another device: Ring a phone next to you and read your number off their incoming call screen, as long as your Caller ID is not set to private.
- Check phone settings:
- iOS: Settings > Phone > My Number.
- Android: Settings > About Phone > Status / Phone Identity.
Official Alternatives
When USSD is unreachable or degraded by an outage, these official MTN channels work:
- MTN Mobile App: On the MTN data network the app detects your SIM and shows your profile and number on the home dashboard. Browsing the app is zero-rated on MTN.
- SIM Toolkit / MTN Services: In the handset menu, open SIM Toolkit (or MTN Services), choose My Services, then My Number.
- MTN WhatsApp Assistant: Message “Hi” to MTN’s official WhatsApp line, 083 123 0011, for self-service account queries.
- In-store: Take your ID and the SIM to an official MTN Retail Store for agent support.
Safety and Privacy
- Never share credentials: A genuine USSD number lookup will never ask for your SIM PIN, account password, bank details, or a one-time PIN.
- Beware of scams: Do not dial unverified USSD strings forwarded by SMS or social media promising free airtime. They can subscribe you to premium content or move your airtime balance.
- Fraud reporting: If you suspect activity on your account, call MTN Customer Care on 135, free from an MTN SIM, or use MTN’s official fraud channels.
Frequently Asked Questions
How do I check my MTN number?
The verified code for checking an MTN South Africa number is *123*888#. You can also dial *123# or *135# and work through the self-service menu.
Which SIM slot must be selected on a dual-SIM phone?
The slot holding the active MTN SIM, chosen at the moment you press dial. Running an MTN USSD code through a non-MTN SIM returns an “Invalid MMI Code” or service error.
Will the number appear on-screen or by SMS?
On screen. *123*888# returns an immediate USSD pop-up, not a text message, so note the number before closing the box.
Does it work on a new or unregistered SIM?
No. The SIM has to be registered under South African RICA law and provisioned on the network first. An unregistered SIM cannot open a USSD session with the towers.
What should I do if the MTN USSD route does not work?
Send a free Please Call Me (*121*number#) to a nearby phone, check Settings > About Phone on your handset, or open the zero-rated MTN App to read your registered number.
