How to migrate a utility billing system without losing customers or revenue

Why billing migrations hurt utilities

A billing system, or CIS as the water industry and the Americans call it, is not just software. It is the revenue engine, the regulatory record and the customer relationship in one place. When a migration goes wrong, the symptoms are always the same: accounts that cannot be billed, customers who cannot be served, and a finance team that can no longer trust its own numbers. Almost none of that is caused by the new platform. It is caused by what the utility brought to it.

The five disciplines that decide the outcome

Data first, and honestly. Reconcile customer, meter and consumption data to a trusted source before the programme starts, not during it. Every migration I have led or rescued was made or broken here. The gaps you find early are tasks; the gaps you find at cutover are emergencies.

Rationalise before you migrate. Legacy estates accumulate tariff variants, exceptions and undocumented edge cases for decades. Carrying them all across is how a clean platform inherits a dirty estate. Kill what you can, document what you must keep, and make the commercial decisions deliberately.

Move in cohorts, never big bang. Controlled waves of accounts, each proven before the next moves, with a rollback that has actually been tested. A big bang with no way back is not a bold plan, it is an unpriced bet with your revenue.

Reconcile everything, prove nothing is lost. Every account, every balance, every meter, counted out of the old estate and counted into the new one, with the differences explained. This is tedious, and it is the difference between a migration and a scandal.

Prepare the operation, not just the system. Your agents, your settlement team and your finance close all change on day one. Design the target operating model, train against reality, and plan the legacy decommissioning so you are not paying to run both estates indefinitely.

Where the platforms fit

The destination matters less than most vendor debates suggest. Whether you are moving onto Kraken, replacing an ageing Gentrack or Junifer estate, or leaving SAP IS U ahead of its 2027 deadline, the five disciplines above are identical. What changes is who is accountable for them, and the honest answer is that they belong to you, the utility, not to the vendor and not to the integrator. That is why independent, client side leadership on a migration pays for itself many times over.