What It Costs a Business to Integrate M-Pesa, Start to Live

Picture a hardware shop in Eldoret that asks customers to pay by M-Pesa on the website. Behind that one button sit four separate costs.

• The shortcode: the paybill or till number that receives the money.
• The developer time to connect, test and go live.
• The fee on each sale, which runs as long as you trade.
• The upkeep when a callback fails, a rule changes or reconciliation needs a fix.

This guide is part of our series for business owners. The overall budget for an app is in how much it costs to build an app in Kenya. Here we stay on M-Pesa alone.

A till (Buy Goods) is the number a customer types when paying a shop. A paybill is the business number plus an account number, such as an invoice or a student admission number. Both can be used by an app.

	Till (Buy Goods)	Paybill
Typical use	Shops, restaurants, services paid at the counter or online	Rent, school fees, utilities, subscriptions, loan repayments
What the customer enters	Till number and amount	Paybill, account number and amount
Matching money to a customer	By phone number or order reference in your system	By the account number the customer typed
Fee structure	Published bands	Agreed with Safaricom for your business

The choice changes how you match each payment to a customer. A paybill carries an account number you can use as the match. A till depends on the reference your app creates and the phone number the payment came from.

If you already know your shortcode type and want a developer to take it live, you can talk to Mctaba Labs about a payments integration.

Fees are the cost that never ends. Work them out per month, not per sale.

For a till, reporting on Safaricom's August 2026 change lists Buy Goods collections up to KES 500 as free, 0.55 percent from KES 501, and a flat KES 200 above KES 36,363 (Tech-ish report on the Buy Goods tariff, checked on 3 November 2026). Safaricom did not let us read its own tariff page today, so confirm these against your merchant agreement.

For a paybill, there is no single published rate we can point to. The charge depends on the tariff model Safaricom gives your business. Ask your account manager for the written rate card before you plan around any figure.

Through Paystack, the Kenya price is 1.5 percent per M-Pesa transaction with no setup or monthly fee, and funds settle two working days after payment (Paystack Kenya pricing, checked on 3 November 2026).

For example, imagine a shop collecting KES 1,000,000 in a month through Paystack. At 1.5 percent that is KES 15,000 in fees. The same shop on a till pays 0.55 percent on each sale above KES 500, which is a lower figure on larger baskets. The gap is what the extra developer work buys you.

Also ask who pays the fee. You can absorb it or add it to the price. Check that your price list and your terms say which.

Daraja is Safaricom's developer platform for M-Pesa. You build and test in a sandbox, then ask Safaricom to move your app to production against your real shortcode. The platform documentation sits at the Safaricom Daraja portal.

1. Have a live shortcode. Your paybill or till must already exist and be active.
2. Build against the sandbox. The test environment uses a shared test shortcode and fake phone numbers.
3. Choose the products you need. A customer prompt on their phone is STK Push. Incoming-payment notices come through C2B. Payouts use B2C.
4. Register your callback URLs. These are web addresses on your server where Safaricom reports each result. They must be public, secure and quick to reply.
5. Request go-live. You apply through the portal for your production credentials, then switch your keys.
6. Run real small payments. Pay yourself a few shillings, check the callback, check the reconciliation and keep the receipts.

Our developer notes cover the detail: Daraja from sandbox to production, M-Pesa callback URLs and STK Push explained.

Where time goes

Writing the payment call is the short part. Most hours go on the callback that arrives late or twice, the customer who closes the prompt, and matching each payment to an order. A developer who has done this before saves you the waiting.

We do not publish studio prices. You can still estimate the work by counting what the payment flow must handle.

Piece of work	Ask the developer
Customer pays on the phone prompt	What if they enter the wrong PIN or ignore it?
Result arrives	What if the callback comes twice, or never?
Match payment to order	What if the customer pays the wrong amount?
Refunds and reversals	Who triggers them, and how are they recorded?
Daily reconciliation	Does the finance team get a report that matches Safaricom's statement?
Security	How do you check a callback is really from Safaricom?

A quote that covers only "STK Push" has left out most of the table. Read our notes on M-Pesa payment reconciliation and securing payment webhooks to see what a complete job includes.

The amount is stored as an integer in cents in many systems, because decimals in money cause bugs. Our note on handling money in code explains why.

Paystack is a payment company that already holds the connections. You integrate once with Paystack, and it handles M-Pesa and cards for you. Its documentation is at Paystack docs.

All of mctaba.com's own M-Pesa payments run through Paystack. We chose that route for our own site because it cut build time and gave one dashboard for cards and mobile money.

When it fits

• You want to accept both M-Pesa and cards on one page.
• Your monthly volume is modest and the percentage fee costs less than a month of developer time.
• You want to launch in weeks, not months.

When a direct Daraja link fits

• Your volume is high and the percentage fee is a large monthly line.
• You need a paybill with your own account numbers, such as admission numbers or member numbers.
• You need payouts to many phone numbers, such as wages or commissions.

Many businesses start on an aggregator and move to direct rails when volume justifies it. That path works only if your first build keeps payments behind one clean boundary in the code, so the swap touches one part. Ask your developer how they will do that.

If you later sell outside Kenya, the answer widens. See one checkout for M-Pesa, MoMo and cards across Africa.

After go-live, someone must watch the payments. A failed callback is a customer who paid and got nothing, which is the worst phone call a shop owner takes.

1. Name who checks failed payments each morning.
2. Keep the Safaricom statement and your system's report side by side every month.
3. Keep credentials in your business's name, not the developer's.
4. Agree who is called when Safaricom changes a rule.
5. Budget a small monthly retainer or a block of hours.

If you run a till at a restaurant or shop, the receipt side matters too: see eTIMS integration for restaurants and shops for how M-Pesa and tax receipts fit together.

Our overview of the stack behind this is in the M-Pesa integration guide. If you are comparing builders, 12 questions to ask before you hire a software studio lists what to ask about payments in particular.

Bring your shortcode type, your monthly volume and the list of flows: pay, refund, payout, reconcile. With those four, any competent team can give you a fair estimate.

When you are ready, talk to Mctaba Labs about a payments integration. We will tell you honestly whether Paystack or a direct link fits, and why.