Nigeria's harmonised telecom short codes give MTN, Airtel, Glo and 9mobile users a common starting point for support, airtime, recharge, data, borrowing, sharing, subscription control and NIN-SIM services. This guide explains why the codes were standardised and provides a clear task table, including 300, *310#, *311#, *312#, *323# and related routes. Each example shows what to dial and what confirmation
Use these codes on MTN, Airtel, Glo and 9mobile for the common task shown. The provider still controls eligibility, plans and the menu behind the code.
The complete everyday code list
| Need | Code or route | What it does |
|---|---|---|
| Customer care | 300 |
Call provider support |
| Borrow services | *303# |
Borrow airtime or data if eligible |
| Stop VAS | *305# |
Review and stop value-added services |
| Airtime balance | *310# |
Show main airtime balance |
| Recharge | *311*VOUCHER-PIN# |
Load a physical recharge voucher |
| Data plans | *312# |
Open available data offers |
| Share services | *321# |
Open supported airtime/data sharing |
| Data balance | *323# |
Check active data buckets |
| NIN-SIM services | *996# |
Open linkage and registration options |
Do this in order
- Select the intended network SIM on a dual-SIM phone.
- Dial the exact code shown for the task.
- Read the provider menu because plan and option numbers can differ.
- Before paying, confirm price, allowance, validity, recipient and renewal.
- Wait for the provider confirmation and check the relevant balance.
- Save the reference and call 300 if a debit occurs without value.
Expected result
The code should open the relevant provider menu or display the requested balance. It does not make every network’s plans, prices, eligibility or support process identical.
When that route fails
Use the provider’s official self-care app, website or service centre. For identity mismatches, use official NIN and network channels rather than an unofficial agent.
Quick answer
Nigeria’s main harmonised mobile codes are 300, *303#, *305#, *310#, *311#, *312#, *321#, *323# and *996#. They cover support, borrowing, subscriptions, balances, recharge, data, sharing and NIN-SIM services across the major networks.
What harmonised means and what it does not mean
Harmonisation gives subscribers a common entry point for the same kind of service. Someone moving from MTN to Airtel, Glo or 9mobile does not need a completely unrelated number just to check airtime or open data plans. This reduces memory errors and makes public education easier.
It does not merge the operators. Coverage, prices, bundles, borrowing eligibility, sharing rules, SIM records and customer support remain provider-controlled. The screen displayed on a subscriber’s line is the current transaction offer.
Recharge and balance checks
Dial *310# to check airtime. To load a voucher, use *311*VOUCHER-PIN# and replace the words with the actual digits. Keep the card until the success message appears. A failed voucher should not be photographed and posted publicly because another person may redeem it.
Dial *323# for data balance. A reply can contain main data, bonuses and separate expiration dates. Read every line before concluding that data is missing.
Buying and sharing data
*312# opens the provider’s current data menu. Compare price, allowance, validity, usage restrictions and renewal. Select the correct SIM before dialling and the correct recipient before gifting. If the provider shows an offer only for that line, do not assume another subscriber will receive it.
*321# opens supported share services. The menu may distinguish airtime transfer, data gifting and shared bundles. Confirm which one you are using because they move different kinds of value.
Borrowing, VAS and customer support
*303# opens borrowing options where the subscriber is eligible. The provider may show a service fee or repayment condition; read it before accepting. A line with no offer cannot be made eligible by paying an online agent.
*305# helps review or stop value-added services. Keep the cancellation message. When deductions continue, call 300, request a complaint reference and provide dates and amounts without sharing an OTP or SIM security code.
NIN-SIM options need extra privacy
*996# opens provider NIN-SIM services, but a successful menu submission may not fix a spelling, date-of-birth or ownership mismatch. Use the network’s authorised centre and NIMC route for formal record corrections. Keep a NIN slip private and redact it before sending evidence.
A social-media account that offers instant unblocking in exchange for an OTP, payment or full NIN image is not a safe shortcut. Start from the network website or service centre.
Old codes, invalid MMI and timeouts
An old provider code may have been replaced, retained for a special service or removed. Try the harmonised entry listed at the top. On a dual-SIM phone, make sure the request leaves through the intended line. Weak signal can also produce connection or invalid-MMI messages.
If a session times out after payment, check the balance and confirmation before starting again. Repeating a purchase can create a second debit or a duplicate bundle.
Three practical uses for harmonised codes
The following examples explain three practical uses for harmonised codes and show how the guidance applies in different situations.
1. Old airtime balance code stops working
The subscriber uses *310# on the intended SIM and receives the current balance instead of trying several blog lists.
2. Unwanted content deduction
The subscriber opens *305#, cancels the service shown, saves the message and calls 300 with dates and amounts when another deduction appears.
3. Data purchase succeeds but browsing fails
The user checks *323# first. If the bundle exists, the next checks are data settings, signal and provider support rather than buying again.
Official sources for this guide
The code table is checked against an official provider guide that publishes the unified list and against Nigerian regulator information.
Remember the task, then remember one code
The list is useful because each common task now has one recognisable entry point. Select the correct SIM, read the provider’s live menu and save the result. That is safer than relying on a screenshot of an old code chart.
Open the Network Finder or read the separate MTN, Airtel, Glo and 9mobile profiles.
Verification record
- Last fact-check
- July 18, 2026
- Method
- Official provider or regulator sources reviewed where available; live menus control account-specific actions.
- Reviewed by
- Nigeria USSD Codes Editorial Team
Primary official sources:
Article note
Last reviewed: July 18, 2026. This independent guide is informational and does not replace instructions from your bank, telecom provider, regulator, or service provider. Verify sensitive actions through an official channel before sending money or sharing information.
Nigeria USSD Codes Editorial Team
Nigeria USSD CodesThe Nigeria USSD Codes Editorial Team researches, reviews and maintains practical guides using official provider and regulator sources where available. Corrections are checked before publication, and sensitive actions are directed back to the responsible provider.