How to buy Safaricom airtime via M-Pesa (and why paybill isn't the right tool)

Buying airtime is one of the most common M-Pesa actions in Kenya — Safaricom users do it billions of times a year. There's a common misconception that you need a paybill to buy airtime. You don't — Safaricom built a dedicated airtime-purchase flow that's faster, free of paybill fees, and works for both your own line and others. This guide clears up the methods and costs.

The four ways to buy Safaricom airtime

Method 1: Direct USSD (*544#)

The simplest method, works on any phone:

1. Dial *544# from your Safaricom line.
2. Choose “Buy Airtime”.
3. Choose your own line or another Safaricom line.
4. If another, enter the recipient's phone number.
5. Enter the amount (KES 10 minimum, no maximum within your M-Pesa balance).
6. Choose payment: M-Pesa balance.
7. Enter your M-Pesa PIN, confirm.

Airtime arrives in seconds. You receive an SMS confirmation. Free of M-Pesa transaction fees — Safaricom subsidises airtime purchases through M-Pesa as a strategic cross-promotion.

Method 2: M-Pesa app — “Buy Airtime”

Open the M-Pesa app, choose “Buy Airtime” from the home screen. Same flow as USSD but with a touchscreen UI. Fingerprint or face authentication replaces PIN entry, which is faster.

Method 3: Topping up another network (Airtel, Telkom)

You can also buy Airtel or Telkom airtime via M-Pesa. Same *544# menu — when prompted for the recipient's line, enter an Airtel (07xx) or Telkom (077x) number. The system detects the destination network and deducts from your M-Pesa balance.

Useful for: gifting airtime to friends on different networks, helping family members who only have one network's SIM, or for your own backup SIM.

Method 4: Sambaza (peer-to-peer airtime)

Sambaza lets you transfer airtime from your existing balance to another Safaricom line — useful when you have airtime but the recipient doesn't have M-Pesa. Dial *145#, enter the recipient's number and amount. There's a small Sambaza fee (KES 5-10 depending on amount). Less common in 2026 since most Kenyans have M-Pesa, but still useful in edge cases.

Why there's no “airtime paybill”

Some Kenyans search for “Safaricom airtime paybill number” — there isn't one. Airtime is a Safaricom product accessed through the M-Pesa menu's dedicated Buy Airtime flow, not through the Pay Bill flow.

If you tried to use a paybill (e.g., 100100 — which is Safaricom Postpaid, a different product), the money would land in suspense or fail entirely. Safaricom Postpaid is for paying postpaid mobile phone bills, not for buying prepaid airtime.

Airtime bonuses and promotions

Safaricom periodically runs airtime-bonus promotions where buying airtime via M-Pesa earns extra airtime, data, or M-Pesa cashback. Check the Safaricom app's “Offers” tab or the dialler menu *544*1# for current promotions.

For business users with multiple SIMs, Safaricom offers bulk airtime purchase via the M-Pesa for Business platform, which has its own pricing.

Airtime vs data bundles vs voice bundles

Three different things, all bought through similar M-Pesa flows:

• Airtime — generic credit on your line. Can be used for voice, SMS, or data, but at standard out-of-bundle rates which are expensive.
• Data bundles — buy via *544# > Buy Bundles, or in the M-Pesa app > Buy Bundles. Specific MB/GB amounts at fixed prices. Significantly cheaper than using airtime for data.
• Voice bundles — minutes-only or minutes-plus-SMS bundles. Buy via same menu.

For typical use: buy data and voice bundles for daily use, keep some airtime for backup. Don't use airtime for data — it's 5-10x more expensive than buying a data bundle.

Paying Safaricom postpaid (the actual paybill)

If you have a Safaricom postpaid contract (you pay monthly for usage), that is paid via paybill 100100. Use:

• Safaricom Postpaid: paybill 100100
• Account: your Safaricom postpaid line number

This is for monthly bill settlement, not for airtime top-up. The two products serve very different needs.

For diaspora users sending airtime home

If you're sending money home that family will use for airtime, the cleanest pattern is:

1. Send M-Pesa to the family member's line (via Wise, Sendwave, etc.).
2. They use *544# from their phone to buy airtime out of that M-Pesa balance.

Some remittance services let you buy airtime directly for a Kenyan number — e.g., Wise has limited airtime-purchase support, MFS Africa has a dedicated airtime product. These skip the M-Pesa middle step but offer less flexibility (the money becomes airtime immediately, with no other use).