Estate prepaid meter apps: how they work, the rules and the cost

Why shared meters end in fights

In many estates and multi-tenant buildings, one Disco meter or one bulk supply feeds every flat. When the bill comes, someone splits it: equally, by number of rooms, or by guesswork. The flat running three air conditioners pays the same as the couple who travel all week, and everyone suspects someone else.

Then come the extras. Street lights, the borehole pump and the gatehouse all sit on the same bill. Tenants who move out leave their share unpaid. The estate manager becomes a debt collector, and the residents’ WhatsApp group becomes a courtroom.

Prepaid sub-metering fixes both halves of the problem. Each flat pays for what its own meter records, so the argument about measuring ends. And because units are bought before they’re used, there are no debts to chase.

First, check whether you need to sell electricity at all

There are two ways to meter an estate, and they lead to very different projects.

If each flat can get its own Disco meter, that’s the simplest legal route: the estate stays out of the electricity business. Discos install meters under several NERC schemes, including Meter Asset Providers: companies holding a NERC permit to finance, supply, install and maintain meters. Prices and refund terms under that scheme have changed more than once since NERC deregulated meter prices in 2024, so ask your Disco what applies today. Metering is far from complete: at the end of March 2026, about 7.3 million of 12.4 million registered electricity customers had a meter, according to NERC’s first-quarter 2026 report.

The rest of this guide is about the second set-up, where the estate buys power in bulk (or generates its own) and sells it on through sub-meters. If your flats already have Disco meters and you only want tenants to buy Disco tokens in an app, that’s a bills-payment product, closer to the model in our guide on starting a VTU business.

How a sub-meter and app system works

1. A meter in every flat. Each flat gets a prepaid sub-meter wired after the estate’s bulk meter. Choose meters that follow STS, the open prepaid standard behind the meters Nigerian Discos had to update in 2024.
2. The vending system holds the keys. Every meter is registered in your meter vendor’s vending system, which holds the encryption keys that make a token work on one meter only.
3. The tenant signs up and chooses an amount. The estate office links each account to a flat and a meter, and the app shows how many kilowatt-hours an amount buys at the current rate before anyone pays.
4. They pay. Card, bank transfer or USSD through Paystack or Flutterwave, settled into the estate’s own account.
5. The server requests a token. Once the gateway confirms the payment, the app’s server asks the vendor’s vending system for a token for that meter, through its API.
6. The token arrives. It shows in the app, goes out by SMS, and stays in the tenant’s history, so a lost message is never a lost purchase.
7. The office sees every sale, matched to the flat, the payment and the token.

What the app needs to do

For tenants

• An account per flat, with room for more than one phone number in family or shared flats.
• Buying units with Paystack or Flutterwave, with the rate and the units shown before payment.
• Token delivery on screen and by SMS, with a resend button for when an SMS is delayed.
• Purchase and usage history: every token, amount, rate and date, with receipts to download.
• Low-balance alerts. True alerts need meters that report their readings (more on that below). With standard keypad meters, the app can only remind people based on how often they usually buy.
• A way to report problems, such as a token the meter rejects, tracked until it’s resolved.

For the estate office

• A register of flats, meters and tenants, with move-in and move-out dates.
• Tariff settings with an approval step and a history, so every rate change is on record.
• Sales and reconciliation reports: units sold per flat, money received, gateway fees, and the total against the Disco bill for the same period.
• Failed-vend handling: retries, then an automatic refund when a payment succeeds but no token comes back.
• Staff roles and an audit log, so no single person can change rates, issue free tokens or delete records unseen.
• Notices to every resident or one block: planned outages, tariff changes, meetings.

Optional: service charge and water

Once residents are used to paying for electricity in the app, it can carry other bills: service charge, levies and water. STS is also used for prepaid water meters, according to the STS Association, so a metered borehole supply can follow the same pattern; unmetered bills need only an invoice, a payment link and a receipt.

Tenant names, phone numbers and usage records are personal data under the Nigeria Data Protection Act 2023. Collect only what the system needs, explain why in a privacy notice, and limit which staff can see what.

Tokens, meters and vendor APIs

STS, the Standard Transfer Specification, is published as IEC 62055-41. It’s an open standard, so meters from different manufacturers can work with one sales system. Its security rests on encryption keys: the STS Association’s guide for vending suppliers says anyone selling tokens needs a letter of permission from the key holder for those meters, a key file from a key management centre and a security module. In practice your app doesn’t make tokens. It asks your meter vendor’s vending system for them.

That makes the vendor’s API the most important thing you buy. If a vendor only offers a desktop program for an office clerk, it can’t power an app that sells a token at midnight. Ask for the API documentation and a test account before you buy a single meter.

STS is also one-way. The STS brochure describes IEC 62055-41 as a protocol for one-way token carriers: tokens travel to the meter, and nothing comes back. So with ordinary keypad meters, the app knows what each flat bought, not what’s left. Live balances, real usage charts and remote disconnection need smart meters with a communication module and a vendor platform that shares their readings.

Meters and vending software need upkeep too. STS meters needed a key change before a token counter rolled over on 24 November 2024, and NERC ordered Discos to finish the work, with daily penalties for each meter not migrated from 1 January 2025. An estate system carries the same kind of risk, so ask your vendor how it handled that date.

Questions to put to any meter vendor, in writing:

• Is the meter STS-compliant, and is the model certified by NEMSA, the agency that tests and certifies electricity meters?
• Does your vending system have an API? Send the documentation, a test account and your charges.
• Can the meter report readings remotely, and how? What does that add per meter?
• Who holds the keys for our meters, and what happens if we change vendor?
• How did you handle the 24 November 2024 token rollover for meters like these?
• What are the warranty, the replacement time and the installation price per flat?

Can an estate resell electricity? What the rules say

Here is what we found when we checked the law and NERC’s rules on 30 October 2026.

The law needs a licence for trading. Section 63 of the Electricity Act 2023 says nobody may engage in the business of electricity distribution, supply or trading without a licence. The exceptions are narrow: generation of up to 1 MW at a site, distribution networks of up to 100 kW at a site, and activities licensed by a state under its own electricity law. The Act defines trading broadly enough to include buying electricity to resell. NERC can order an unlicensed operator to stop and have it disconnected, and the offence carries fines and up to five years in prison.

Read literally, a bulk-supplied estate that sells units to residents is trading. Whether an estate that only recovers its costs is “in the business of” trading is exactly the question to put to your regulator. We found no NERC regulation or order written for estates that sub-meter residents on a bulk supply, and none that sets the price they may charge. So the honest answer is that it’s unsettled.

Your regulator may be your state. States can now set up their own electricity regulators for activity wholly inside the state, and those regulators handle licensing, tariffs and consumer protection there, as NERC’s guide to who does what explains. By the end of March 2026, NERC had handed oversight to 16 states. If your state has its own regulator, ask it; if not, ask NERC.

Private networks have their own rules. NERC’s 2012 regulations for independent distribution networks license private networks, and where such a network is connected to a Disco, they make the Disco responsible for buying, installing and vending all the meters in it. NERC’s Mini-Grid Regulations 2026 cover any system with its own generation that supplies more than one customer: systems under 100 kW can simply register with NERC, and bigger ones need a permit, with a tariff worked out on NERC’s model. If your estate also sells generator or solar power to residents, read them.

What to charge

The price you can defend line by line is the rate the estate pays. NERC publishes each Disco’s tariff orders; use the per-kWh rate on your own Disco bill, show it in the app before every purchase, and change it on the day the Disco’s rate changes.

The bulk meter will always record more than the sub-meters add up to, because cables lose some energy and common areas use some. Recover that through the service charge as its own line, with the bulk bill and the sub-meter total shown side by side, not by quietly raising the unit price.

A prepaid sub-meter can’t tell grid power from generator power. If you want different prices for each, you need separate circuits or meters. Otherwise, agree one approach with residents in writing, and remember the mini-grid rules above.

What the estate must not do

• Don’t tamper with or bypass the Disco’s meter, or connect your own meters to the Disco’s lines without authorisation. Both are offences under sections 208 and 211 of the Electricity Act 2023.
• Don’t start selling before you’ve asked. Get your regulator’s answer in writing before launch, and keep it.
• Don’t hide a margin in the unit price. If a resident complains to a regulator, an undisclosed markup is the hardest thing to defend.
• Don’t use meters NEMSA hasn’t certified, or tokens from anything other than your vendor’s authorised vending system.
• Don’t keep residents’ money as a naira balance in the app. Wallets and e-money are licensed activities under the CBN’s mobile money framework. Take payment for each purchase instead, or use a licensed provider’s wallet.
• Don’t use the meter to collect other debts, such as unpaid service charge, unless residents agreed to that in writing in their tenancy or estate rules.

What it costs

Our prices cover the software. Everything else is quoted by whoever supplies it, so collect those quotes before you commit.

Projects are paid by milestone, usually 40–50% to start, and you own the code and accounts after the final payment. Every starting price is on our pricing page, and our guide to what an app costs in Nigeria explains what moves a quote up or down.

Gateway fees on a token purchase

Small purchases are where fees bite. Here’s what each gateway takes on three example purchases, using the prices on Paystack’s and Flutterwave’s pricing pages in October 2026. Paystack charges 1.5% + ₦100 on local payments, waives the ₦100 under ₦2,500 and caps the fee at ₦2,000. Flutterwave charges 2% on local payments, plus 7.5% VAT on the fee.

Neither is cheaper at every amount. Decide early whether the estate absorbs the fee or adds it to the purchase, and show it before payment either way.

Three questions to settle before anyone writes code

1. Which meters, and does the vendor have an API? Everything else depends on this. If meters are already installed, find out whose vending system they sit behind and whether it can talk to an app. If they aren’t, choose the vendor for its API and support, not only the meter price.
2. Who holds the money? Payments should settle into an account in the name of the estate or its facility company, never a staff member’s. Decide who can issue refunds, who signs off the monthly reconciliation, and who pays the Disco from the takings.
3. What is the tariff? Agree the rate (the Disco’s, as above), how common areas and losses are recovered, how generator power is treated and who approves changes. Put it in the estate rules before the app goes live.

Settle one more at the same table: who owns the meters when a tenant leaves or the estate changes manager.

Mistakes that sink estate metering projects

• Buying meters before checking the API. An estate full of meters that can only be vended from a desktop program leaves your app with nothing to call.
• Promising live balances on keypad meters. STS tokens go one way. If residents expect to see what’s left, budget for smart meters.
• No plan for failed vends. Networks drop. Tie every token to its payment reference so a retry returns the same token instead of charging twice, and refund automatically when no token can be issued.
• Ignoring losses and common areas. If the unit price only covers what the sub-meters record, the estate quietly pays the difference every month.
• Launching without the residents. Hold a meeting, explain the rate and the rules, and pilot the system on one block first.

Who can build it

We haven’t built an estate metering app. We build the rest of the system: Android and iOS apps from one Flutter codebase, Paystack and Flutterwave payments, SMS delivery, and admin dashboards with audit logs. The nearest thing we’ve built is NaijaTopup, a VTU and bills platform with an admin app.

If you work with us, we’d start with a working test against your meter vendor’s API, before any screens are designed, so you learn early whether the integration holds. See mobile app development for the tenant app and software development for the billing platform, or contact us with your meter brand and the number of flats.

Frequently asked questions

General information, not legal advice. Rules change; check the current version with NERC or your state electricity regulator before you act.