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PAYGO and mini-grid software

PAYGO Solar Software and Mobile Money Integration

A pay-as-you-go solar provider needs payments, device control and customer records to agree with each other, across thousands of small transactions. Vascoh builds custom PAYGO and mini-grid billing software that connects mobile money, device locks and your field team in one system.

5.11 million

PAYGo off-grid solar units sold in 2025, up 48% and equal to cash sales for the first time.

Source: GOGLA, Global Off-Grid Solar Market Report (2025 data), as reported by TaiyangNews
$2 trillion

Value of mobile money transactions in 2025, double the $1 trillion reached in 2021.

Source: GSMA, State of the Industry Report on Mobile Money
25.7%

Share of 2.3 billion registered mobile money accounts that were active monthly in 2025.

Source: GSMA, State of the Industry Report on Mobile Money

What does PAYGO solar software have to do?

At minimum it holds the customer and contract, receives each payment, converts it into credit, and tells the device to run or lock. Around that sit agent management, arrears collection, inventory, and the reports that lenders and funders ask for.

The market is large. GOGLA reported 5.11 million PAYGo units sold in 2025, up 48% and matching cash sales for the first time. Established platforms exist, and many operators use them. Custom work usually makes sense when your product mix, tariff structure or country regulations do not fit what a platform supports.

Arrears handling deserves its own design. Grace periods, partial payments, a reduced-service mode and a clear unlock rule after a late payment all change collection rates and customer trust. Writing those rules as configuration, not code, lets operations staff tune them as the portfolio matures.

  • Contract and customer records with KYC fields
  • Payment-to-credit engine
  • Device lock and unlock
  • Agent and field collection tracking
  • Funder and portfolio reporting

How do device lock and unlock work?

Each PAYGO device, such as a solar home system, has a controller that either contains a GSM modem or accepts a code. In connected devices, the platform sends a command through the manufacturer's cloud API or a device protocol to enable or disable the unit. In offline devices, the customer enters a numeric token generated by the platform that adds days of credit.

Both need care. Connected locks fail when the device has no signal, so the software must show the last confirmed state and retry. Token generation must follow the manufacturer's algorithm and keep keys in a secure store. Many operators use hardware from different makers, so the software normalizes each into one status model.

Security matters because a lock command is a power over a customer's lighting and phone charging. Commands should be authenticated, rate limited and logged with the staff member or rule that triggered them, so a mass lock by mistake can be traced and reversed.

How are M-Pesa and MTN MoMo collections integrated?

Safaricom's M-Pesa offers Daraja APIs, including paybill or till confirmation callbacks and STK Push to prompt a customer on their phone. MTN MoMo offers a Collections API through its developer portal. Each pushes a callback when a payment completes, and your server must verify, deduplicate and credit it.

Reconciliation is the hard part. Customers pay the wrong account number, pay twice, or pay from another person's phone. The system needs rules for unmatched payments, a queue for staff to resolve them, and a daily match between provider settlement statements and credited amounts. GSMA reported mobile money transactions reached $2 trillion in 2025, but only 25.7% of the 2.3 billion registered accounts were active monthly, so customer payment habits vary and reminders by SMS matter.

How does mini-grid billing differ?

Mini-grids usually bill by energy used rather than by a fixed installment. Smart meters report consumption, and customers buy prepaid units or are billed after reading. The software must ingest meter data, price it against a tariff (which may be tiered or time-based), apply payments and handle disconnection rules. Where meters are offline for hours, delayed readings must not double bill.

What should you confirm before building?

Check the mobile money API access terms in each country, data protection law for customer records, and whether your lenders require specific reporting formats. Vascoh has not published client work in this area, so scope starts from your own process and the vendor documentation, with a sandbox test before any live collection.

How a project runs

From first call to working system.

Step 01

Define the payment and device rules

Document tariffs, grace periods, lock rules and how each device type is controlled, then list the mobile money products you collect through.

Step 02

Build against sandboxes

Vascoh builds the payment callbacks, credit engine and device commands against provider sandboxes, with reconciliation reports from the first day.

Step 03

Pilot on a small portfolio

A limited group of live customers runs through the system while staff compare its balances against current records before the full migration.

Questions

Common questions

What is PAYGO solar software?

It manages pay-as-you-go solar contracts: customer records, payments, credit balances and remote locking or unlocking of devices when a customer is paid up or in arrears.

How does M-Pesa integrate with a PAYGO system?

The platform uses Safaricom's Daraja APIs, such as STK Push and payment confirmation callbacks, then matches each payment to a customer account and adds credit.

How do PAYGO solar devices lock?

Connected devices receive a disable command over GSM through a manufacturer or platform API. Offline devices stop working when the entered token's days run out.

Can mini-grid billing use mobile money?

Yes. Customers buy prepaid units or pay bills through mobile money, and the billing system credits the meter or account once the provider callback is verified.

Contact

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Describe the systems and the manual work, and we will tell you what is realistic to build and what is not.

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