Out of airtime and need someone to call you back? MTN's version of Please Call Me is officially listed as Callback, and it costs nothing to send.
The code
Example: to reach 071 234 5678, dial *121*0712345678# and press the call button.
You can also dial *121# on its own and follow the on-screen prompts, which is easier if you are working from your contact list.
This is confirmed on MTN's own official USSD codes page.
Step by step
- Open the phone dialler on your MTN handset.
- Type *121* then the number you want to reach, then #.
- Press the call button. This is a USSD string, not a call — it will not use airtime.
- Wait for the confirmation message on screen.
- The other person receives a text asking them to call you, showing your number.
Cost and limits
MTN's official page does not state a cost or a daily limit for Callback. Third-party sources have long described it as free with a cap of around five per 24 hours, but that figure comes from older articles and has not been re-confirmed by MTN, so treat it as a rough guide rather than a fixed rule. In practice, you will get a message telling you when you have reached the limit.
When it does not work
| What you see | Likely cause | What to do |
|---|---|---|
| "Connection problem or invalid MMI code" | Number formatting, or the dialler treated it as a call | Retype without spaces, include the leading 0, end with # |
| Daily limit reached | You have sent too many today | Wait until the limit resets, or use another method below |
| Nothing arrives on the other phone | Recipient is off, out of coverage, or on a network that delays delivery | Messages usually deliver when they come back into coverage |
| Fails on a dual-SIM phone | Sent from the wrong SIM slot | Choose the MTN SIM when prompted, or set it as the default for calls |
| Fails while roaming | USSD often does not work on foreign networks | Use WhatsApp or email instead |
Free alternatives when Callback is not an option
- Missed call. One ring costs nothing and shows your number on their screen.
- WhatsApp over Wi-Fi. Costs no airtime and no mobile data if you are connected to Wi-Fi.
- Ask for airtime. MTN's Me2U service (*136*3#) lets someone send you airtime, data or SMS bundles, and lets you request them.
A useful side-effect: finding your own number
Because the Callback message shows your number to the recipient, this is the quickest way to find out your own number when you have forgotten it — send one to a friend and read it off their screen. We cover the other methods in how to check your MTN number.
Other MTN codes worth knowing
| What you want | Code |
|---|---|
| Callback / Please Call Me | *121*[number]# or *121# |
| Balance | *136# |
| Detailed balance | *136*1# |
| Me2U — send or request airtime/data/SMS | *136*3# |
| Bundle management | *136*5# |
| Me4U — recharge another number with a voucher | *141*[voucher]*[number]# |
| Customer care | 135 / 083 135 |
| Fraud line | 083 135 4357 |