STK Push is an M-Pesa payment method where a business's system sends a payment prompt directly to a customer's phone. The customer sees a pop-up asking them to enter their M-Pesa PIN to approve the exact amount. They don't need to open an app, dial a code, or know the business's Paybill or Till Number themselves. It's the method most Kenyan businesses use for fast, low-friction payments both in person and online.
What STK Push actually stands for
STK stands for SIM Toolkit: a menu system built into every SIM card that lets the mobile network send interactive prompts straight to a phone's screen, independent of any app. "STK Push" is Safaricom's term for pushing an M-Pesa payment request through this channel. When a business triggers an STK Push, the customer's phone displays a prompt showing the amount and asking for their PIN: without the customer having had to do anything to initiate it themselves.
Because it works through the SIM Toolkit rather than the M-Pesa smartphone app, STK Push works identically on a basic feature phone and a smartphone: which matters in a market where not every customer has a data connection or the app installed.
How STK Push works, step by step
- A business's system (a POS, a website checkout, or an app) sends a payment request to Safaricom via the Daraja API, specifying the amount and the customer's phone number.
- Safaricom pushes a prompt to that phone number through the SIM Toolkit. This appears on the customer's screen within seconds, showing the amount and the receiving business.
- The customer enters their M-Pesa PIN to approve the payment, or cancels/ignores it if they don't want to proceed.
- Safaricom processes the payment and sends a confirmation back to the business's system automatically: no manual checking of SMS messages required on the business side.
- The business's system marks the transaction as paid, typically within seconds of the customer entering their PIN.
STK Push vs other M-Pesa payment methods
| Method | How it works | Customer effort |
|---|---|---|
| STK Push | Business triggers a prompt directly to the customer's phone | Enter PIN when prompted: no need to know a Till or Paybill number |
| Manual Till/Paybill payment | Customer opens M-Pesa, selects Lipa na M-Pesa, enters the business's number and amount themselves | Several manual steps; risk of entering the wrong number or amount |
| Send Money | Customer sends money to a personal phone number | Not suited to business transactions: no automatic confirmation to a business system |
The key difference is who does the work: with STK Push, the business's system does the heavy lifting and the customer only has to approve; with a manual payment, the customer has to correctly enter the business's payment details themselves, which is slower and more error-prone.
Where STK Push is used
STK Push shows up in two common settings for a Kenyan business: at a physical till, where a cashier enters the amount and the customer's number and a prompt appears on the spot, and at an online checkout, where a Kenya-compatible payment gateway triggers the same kind of prompt when a customer selects M-Pesa as their payment method. In both cases, the appeal is the same: an instant, low-error way to collect payment without asking the customer to do more than approve a PIN prompt.
For a closer look at how STK Push compares with the Till and Paybill numbers a business needs to receive it, see M-Pesa STK Push vs Paybill vs Till Number and M-Pesa Till Number vs Paybill: Which One to Register.
Frequently asked questions
STK Push, built into your till
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