In Abidjan today, a shop that wants to accept mobile money typically displays several merchant codes on the counter: one for Orange Money, one for MTN MoMo, one for Moov Money, one for Wave. The customer picks the one matching their wallet. If the shop forgot to register with one network, that customer pays cash or leaves.
That row of codes is what non-interoperability looks like from the street. Here is what changes when it goes away.
For the customer: the wallet stops being a walled garden
The most direct effect is the simplest. A customer on one network can pay anyone, on any network, from the wallet they already have.
That sounds small. It changes behaviour. When a wallet can only pay people on the same network, customers keep cash or hold multiple SIMs to cover the gaps. When it can pay everyone, the wallet becomes a place to keep money rather than a place to pass it through. GSMA's industry reports have followed this shift from cash-in-cash-out usage toward digital payments for years 1.
The World Bank's Findex data shows how many adults in Sub-Saharan Africa already hold a mobile money account 3. Interoperability does not add those people. It makes each of their accounts reach further.
For merchants: one code, every customer
A merchant on an interoperable system accepts payment from every wallet through one acceptance point. Three practical consequences:
- Onboarding gets cheaper. One registration, one settlement account, one statement.
- Coverage stops depending on paperwork. The shop no longer loses customers because it did not register with the third or fourth network.
- Reconciliation gets simpler. One stream of payments, one daily total, instead of four.
For online merchants the same logic applies with less drama. A checkout that integrates once and reaches every wallet in a market converts better than one that integrated the two largest networks and hoped.
For operators: competition moves up the stack
Operators worry, reasonably, that interoperability erodes the advantage of having the biggest user base. If a smaller network's customers can pay into your merchants, your merchant acquisition no longer locks customers in.
What actually happens is that competition moves. Operators stop competing on "who can you pay" and start competing on what they do best: agent network quality, pricing, credit and savings products, app experience, merchant tools. The rail becomes shared; the product on top stays differentiated.
Card networks proved this decades ago. Issuing banks share a common acceptance rail and still compete fiercely for cardholders. The rail made every issuer's card more useful, which grew the pie each was fighting over.
When everyone can pay everyone, operators stop competing on reach and start competing on product.
For agents: less cash shuttling
Agents carry the float that converts cash to e-money and back. In a fragmented system, an agent serving several networks has to hold separate float for each, and rebalance them all.
Interoperability does not remove agents, and probably should not. But as more payments stay digital end to end, fewer of them require a cash-out at the far end, and agent liquidity is spent where it is genuinely needed.
For cross-border flows: the hard version of the same problem
Domestic interoperability is a solved problem in several markets. Tanzania's operators interconnected their wallets years ago, and national switches exist elsewhere. Open-source platforms such as Mojaloop were designed to help countries build exactly this kind of inclusive, interoperable instant payment system 2.
Cross-border is harder for three reasons:
- Currency. A Senegalese wallet holds XOF; a Cameroonian wallet holds XAF. Even within CFA zones, that is a conversion between two currencies issued by two central banks. Across Kenya, Tanzania and Uganda it is three floating currencies.
- Regulation. Each payment crosses two regulatory regimes, each with its own limits and reporting rules.
- Settlement. Two operators in two countries need a way to know who owes whom at the end of the day, and to settle it.
That is why remittances into Sub-Saharan Africa have remained more expensive than into any other region in the World Bank's price data 4. Domestic interoperability has not solved the border.
What a cross-border interoperability layer has to provide
From the operator's side, joining a cross-border layer is only worth it if it gives you:
- Addressing. A way to resolve a recipient in another country and learn which rails can reach them.
- A quote before commitment. The sender's operator knows the rate, fee and amount received before the payment moves.
- A single transaction state. Both sides see the same status, through the same state machine, with timeouts that resolve rather than hang.
- Recorded obligations. Who owes whom is written down the instant the destination accepts, and netted on a schedule.
- A certification path. Every participant has proven it handles timeouts, reversals and replays before it carries real traffic.
That list is the design of Ultraner Network, documented on the protocol page. It is built and running in sandbox against simulated participants. No operators are live on it yet, and settlement windows model obligations rather than moving funds between banks. We are describing an architecture you can test, not a network you can already route volume through.
A short scenario
Imagine it working. A trader in Dar es Salaam on Mixx by Yas pays a supplier in Kampala on MTN MoMo.
- The trader's operator resolves the supplier's address through the network directory: Uganda, UGX, reachable via MTN MoMo.
- It requests a quote: TZS amount sent, UGX amount received, fee, rate, expiry.
- The trader sees and confirms the quote.
- The payment is authorized against that quote, executed, and accepted by the supplier's operator.
- At that instant, an obligation from one operator to the other is recorded in the ledger, in the same transaction as the state change.
- At the window's close, all obligations between the two operators in both directions net into one figure.
No bilateral contract between those two operators was needed. Each connected once.
Where to go from here
If you run a mobile money product, the questions worth asking internally are commercial before they are technical. Which corridors do your customers already send through informally? Which merchants are you losing because their customers are on another network? What would you build if reach were no longer your moat?
The architecture is on the network overview. The onboarding path, from sandbox to certification to a human review, is on connect. For the domestic networks Ultraner's merchant product already collects through, see Orange Money and MTN MoMo.
