How to accept M-Pesa payments on your website

Customers are ready to pay you the moment they decide to buy — the last thing you want is a clunky checkout that loses them at the payment step. If you sell in Kenya, M-Pesa is where the money is. This guide walks through the two ways Fortpesa lets you collect it from your own website: STK Push (the customer gets a prompt on their phone) and payment links (share one URL, get paid).

How M-Pesa collections actually work

M-Pesa has no "card number" to type. The equivalent is the STK Push (STK = SIM Toolkit): your system asks the customer for their phone number, M-Pesa sends a prompt to that phone, the customer enters their PIN, and the payment is confirmed back to your system within seconds.

Behind the scenes there are three moving parts:

1. A collection channel — the paybill, till number or bank paybill your money lands on.
2. The prompt — an STK Push sent to your customer's phone with the exact amount.
3. Confirmation — a callback that tells your system the payment succeeded, so you can fulfil the order.

Fortpesa wires all three together. You add a channel once, then every collection after that is a single call.

Option 1: STK Push from your own checkout

STK Push is what you want inside your own website, app or system: the customer enters their phone number on your checkout, presses Pay, and gets an M-Pesa prompt on that same phone.

A real request looks like this:

curl -X POST https://fortpesa.co.ke/api/v1/payments/stk \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "phone": "254712345678",
    "amount": 150,
    "channel_id": 42,
    "reference": "ORDER-1042"
  }'

Three things worth noting:

• amount is whole shillings — 150 means KES 150. No minor units, no surprises.
• channel_id is required — you pick which channel the prompt comes from, so a payment can never land in the wrong place.
• reference shows up as the account reference on the customer's M-Pesa confirmation SMS.

The response gives you a transaction UUID. You then poll GET /api/v1/transactions/{uuid} (or wait for the webhook) until the payment is success or failed.

A two-minute run-through of a live collection on Fortpesa.

Option 2: payment links (no checkout code required)

Not everything needs a full checkout integration. A payment link is a public URL you can share anywhere — WhatsApp, an invoice, a social bio, a printed flyer. The customer opens it, sees your business name and the amount, enters their M-Pesa number and pays.

Payment links are ideal when:

• You sell on social media and chat with customers directly.
• You send invoices manually.
• You want to get paid today, and will integrate the API next week.

You can make a link fixed-amount ("KES 1,500 for order #1042") or open-amount (the customer types what they owe). Both are created from the dashboard in a few clicks.

Which one should you choose?

Most merchants start with a link, then move their best-selling product to an API checkout once volume grows. Nothing is lost in the move — the transactions, receipts and webhooks look exactly the same.

What it costs

The platform publishes its full fee schedule up front — flat tiers by amount, starting with a free band and KES 3 from KES 10 up. You see the exact fee on every transaction before you send a prompt, so pricing never becomes a guessing game.

Get started

1. Create an account — your dashboard is ready in under a minute.
2. Add your first channel (paybill, till or bank deposit) and it is provisioned for you.
3. Either share a payment link or grab your API key and take the API quickstart for a spin.

Want to understand where the prompt comes from first? Read Paybill, till or bank channel — or compare the two collection styles in STK Push vs payment links.