Paybill account numbers for subscriber payments
Should a Kenyan ISP ask subscribers to quote an invoice number or a customer number on its M-PESA Paybill, and what happens to each payment?
By Achekam · · 4 min read · For Telecoms businesses in Kenya
Every month, your subscribers open M-PESA, choose Lipa na M-PESA, enter your Paybill number and then pause at the next field: Account Number. What they type there decides how much work your accounts team does for the rest of the month. Some type their customer number, some type their phone number, some type the invoice number, and some type "internet" or their estate's name.
For a Kenyan ISP or fixed-wireless provider, that one field is the difference between payments that land on the right invoice by themselves and a long list someone has to work through by hand. This article explains how the Paybill account number works, the case for asking subscribers to quote the invoice number versus a customer number, and what Achekam does with each kind of payment.
What the account number is for
Safaricom describes M-PESA Paybill as a cash collection service through which an organisation collects money regularly from customers, who enter the business's Paybill number and an account number that identifies them. Safaricom's Paybill page sets out how the service works and the channels for managing it.
The Paybill number tells M-PESA which business to pay. The account number tells the business who paid and what for. M-PESA passes on whatever the customer types; it is up to you to make that field useful.
Why Paybill suits subscribers
Safaricom says Paybill payments are customer-initiated and suit customers who have an official relationship with the organisation they pay. That describes a subscriber exactly. Unlike a walk-in shopper at a Buy Goods till, a subscriber pays you every month for the same service, has an account with you, and receives an invoice. The account number field exists for precisely that kind of relationship.
The question is which identifier to ask for.
Option one: the invoice number
In Achekam, a Kenyan business can register its Paybill or till so that payment notifications reach its books. A payment that quotes an open shilling invoice number as the account number is receipted automatically against that invoice. Nobody has to look at it.
That is the strongest argument for asking subscribers to quote the invoice number. When it works, the receipt reaches the books without anyone touching it, and the invoice shows as paid.
The drawback is that the invoice number changes every month. Subscribers who save your Paybill details in their phone will save last month's number, and a payment quoting an invoice that has already been paid is no longer quoting an open invoice. It will not be receipted automatically.
Option two: a customer number or anything else
A customer number never changes, which is why many providers prefer it: subscribers learn it once and reuse it. But in Achekam, any payment that does not quote an open invoice number waits in a list for a person to allocate. That includes customer numbers, phone numbers, old invoice numbers and anything else.
Allocating from the list is straightforward: customer payments can be recorded against one invoice or spread across a customer's invoices, a part payment leaves an invoice part-paid, and any extra is held on the customer's account. A receipt allocated to the wrong invoice can be re-allocated later. But each one takes a person's time, and at month-end volumes that time adds up.
Choosing, and making it work
For most subscriber bases, the practical answer is the invoice number, supported by habits that make it easy to use:
- Print it prominently. On each invoice, put a line that says "Pay to Paybill (your number), Account: (invoice number)" near the amount due.
- Say it in the e-mail. When the invoice is sent, repeat the account number in the body of the message, not only in the attachment.
- Keep the customer number as a fallback. Tell subscribers that if they cannot find the invoice number, their customer number still works, and your team will allocate the payment.
- Clear the list daily. Whoever handles receivables works through unallocated payments every morning, so subscribers who used the fallback are not chased for invoices they have paid.
A business creates each invoice and issues it with the next number in its sequence, so the number subscribers quote is the one printed on their invoice.
Prompting the subscriber's phone instead
There is a way to skip the account number field altogether. A Kenyan business on Achekam can send an M-PESA payment prompt to a customer's phone for a shilling invoice, to its Paybill or Buy Goods till, and the payment is confirmed with Safaricom before it counts. The subscriber sees the amount and enters their PIN; there is nothing to type.
A few points to know before you rely on it:
- Only whole shillings are requested, so any cents stay due on the invoice.
- Production use needs Safaricom's Go-Live approval for your shortcode.
- The same phone can be prompted once a minute, so an agent cannot send a string of repeat prompts.
Prompts suit the call-centre moment: a subscriber phones about a suspended line, the agent confirms the overdue invoice, sends the prompt, and the subscriber pays while still on the call.
Reading the Paybill statement
Whatever you choose, the Paybill statement is your check that the books are complete. Safaricom says a Paybill account can be managed from any handset via *234*4#, the M-PESA Business App or a web portal, with real-time reports and statements. Compare the statement for each day with the receipts in your books and the unallocated list: every M-PESA receipt should appear in one or the other. Reconciling M-PESA receipts walks through that check, and Buy Goods or Paybill? explains why a shop might choose differently from a subscription business.
A step for this month
Look at last month's Paybill payments and count how many quoted an open invoice number. If it is a minority, change the wording on your invoices and e-mails before the next billing run, and watch the unallocated list shrink.
General guidance only, not advice on your own circumstances. Tax and payroll rules change: check the current position with the authority or your adviser.
