ENSEK: Billing, customer and flexibility software for energy retailers

Overview

ENSEK started in Nottingham in 2010 as a software supplier to energy retailers. When the private equity firm LDC backed a management buyout in October 2017, it had 65 staff and sold revenue assurance and margin accounting tools to established suppliers, alongside a complete operating system for new entrants to the British market. The customer and billing platform it launched in 2016, Ignition, became the core of the business.

Centrica changed the company's scale. In August 2021 Centrica agreed to move more than seven million British Gas customers onto Ignition; its low-cost digital brand, British Gas Evolve, already ran on it. Three years later Centrica bought the company: LDC announced its exit in July 2024 and the sale completed in September 2024. The same month ENSEK bought Zoa, a home energy management start-up formed after the supplier Bulb went into administration, and with it a team that connects household batteries, solar and EV chargers.

ENSEK now sells its product as an energy orchestration platform: a retail core for billing and customer operations, plus modules for margin analysis, tariff design and household flexibility. Its strongest credential is the migration of British Gas, one of the largest supply books in Britain, onto a platform that also serves other suppliers. The flexibility module is much younger: one published programme of 306 homes stands behind it, against millions of accounts on the billing side.

Offering

Retail core

Three modules run the daily business of a gas and electricity supplier (capabilities). Customer Lifecycle holds the customer record and the service and self-service journeys. Billing Operations is an event-driven billing engine that runs domestic, SME and industrial and commercial accounts on one model, with live balances, time-of-use tariffs built on half-hourly smart data, grouped and multisite business accounts, and prepayment run as its own operating mode with a separate balance ledger, emergency credit and low-balance alerts. Payments and Collections covers payment methods, debt and recovery.

Growth modules

Margin Intelligence reports profitability by customer, tariff and segment. Offer Intelligence lets pricing teams model tariffs against cost data before launch. Both are sold individually on top of the core.

Flexibility Monetisation

The Flexibility Monetisation module, built on the Zoa business and previously marketed as ENSEK Flex, enrols customer-owned solar, batteries, EV chargers and heat pumps, optimises them behind the meter, aggregates them into virtual power plants and automates dispatch into wholesale, balancing, capacity and local flexibility markets, including DSO tenders. The company says it works across more than five markets in Great Britain and Europe and with several manufacturers, but names neither the markets nor the brands. In the Metis programme it also supplied the resident app and fleet monitoring.

Smart DCC Adapter

Announced in December 2025, the adapter automates smart-meter data flows between a supplier's systems and advanced metering infrastructure, meter data management and head-end systems. ENSEK reports that one retailer cut manual interventions by more than 40% with it.

Everything is sold as software as a service. No prices or contract terms are published.

Technology

Architecture

ENSEK describes the platform as modular, API-first, cloud-native and headless, with the front end separate from the back end (architecture). A market abstraction layer sits between the retail core and external market systems and turns market events, settlement signals and regulatory instructions into platform actions. Market rules, tariffs and language sit in configuration rather than code, which is how the company intends to run a platform built for Britain in other countries. Systems connect through event-driven interfaces rather than point-to-point links (platform overview), and the company says the platform handles billions of data points across settlement, billing and margin work.

Hosting and partners

The platform runs on Amazon Web Services. ENSEK reported AWS Advanced Partner status and a completed Well-Architected Review in January 2020. Its partner list names Salesforce for customer relationship management, GoCardless for Direct Debit, SmarterPay and Global Payments for card and payment processing and Experian for credit data, plus CrowdStrike, Datadog and Netskope in its own security and monitoring stack. Solar Power Portal reported in 2021 that British Gas Evolve ran Ignition alongside Amazon and Salesforce software.

Meters and devices

The Smart DCC Adapter links supplier operations to the systems around the national smart-meter network: AMI, meter data management, head-end systems and distribution network data keyed on MPAN and MPRN. Billing runs smart, traditional and prepayment meters on one platform. On the flexibility side, solar and battery systems connect cloud to cloud through manufacturer APIs, with no hub in the home, as in the Metis programme. No public API reference, device compatibility list or service levels are published.

Security

BSI certified ENSEK to ISO 27001 in November 2020 under certificate IS 729036; the scope is not stated. Its auditor A-LIGN reports that ENSEK has since obtained SOC 1 and SOC 2 reports, without stating the report type or period. There is no public trust centre or penetration test summary.

Customers

British Gas

The largest reference is Centrica's British Gas. ENSEK's case study reports moving 7.5 million residential customers, 11 million accounts and 13.5 million meter points off the legacy billing system in a phased programme that began in 2021, with parallel running and continuous validation. It reports a Net Promoter Score of 37, a record for British Gas, contacts per customer at their lowest in a decade, a Trustpilot rating of 4.4 and no regulatory fines or enforcement action from the migration. Independently, LDC said in July 2024 that the platform already served the majority of British Gas domestic customers.

Other suppliers

Before the Centrica sale ENSEK reported more than 30 supplier customers. Good Energy moved its entire business supply book onto Ignition in October 2020, covering small businesses to large industrial users and its PPA and broker work. Trade press in August 2021 named Eneco and Utility Warehouse among the customers, and Utility Warehouse and Good Energy were named again at the Zoa acquisition in September 2024. No new supplier has been announced since Centrica took ownership, and the current status of those contracts is not public.

Metis

The one published flexibility deployment is with Metis, a product of SMS, in Oxfordshire (case study, July 2026). Metis designed, financed and installed 306 solar and battery systems with no upfront cost to households, more than its original target; ENSEK supplied the optimisation engine, data platform and resident app; Oxfordshire County Council led outreach. ENSEK reports that households cut electricity costs by about 35% on average against their pre-installation consumption, and that more than three-quarters of app users open it weekly. The programme won a Net Zero Engagement Award in 2025.

Markets

Great Britain is the home market and the source of every public customer reference. The retail core is built around British industry processes, from smart-meter data flows through the DCC to prepayment, and the about page describes the company as working with utilities across the UK. The flexibility module targets markets in Great Britain and Europe, and the market abstraction layer is designed to carry the platform into other jurisdictions, but no customer outside the UK has been announced. ENSEK is exhibiting at Enlit Europe in Vienna in November 2026 (home page).

There are three kinds of buyer. Licensed gas and electricity suppliers buy the retail core to replace legacy billing across domestic, SME and industrial and commercial portfolios. Retailers and asset owners buy the flexibility module to enrol customer devices and earn from flexibility markets. Energy-as-a-service providers, as Metis shows, use the flexibility module to run household solar and battery programmes on behalf of a local authority area.

The partner ecosystem is technology and payments: AWS for hosting, Salesforce for CRM, GoCardless, SmarterPay and Global Payments for payments and Experian for credit (partners). Its owner is also its largest customer, which gives it a stable base but may weigh on rival suppliers deciding whether to buy from a competitor's subsidiary.

Company

History and ownership

ENSEK Ltd was incorporated in England on 24 February 2010 and is registered at Hounds Gate in Nottingham (Companies House); it also has a London office (about). The company names 2014 as the year of its first outside backing and first customer, and 2016 as the launch of Ignition. LDC backed a management buyout in October 2017 (TheBusinessDesk). The register for the holding company, ENSEK Holdings Limited, records LDC with significant influence from 3 October 2017 until 20 September 2024, when GB Gas Holdings Limited became the owner of more than 75% of the shares (register). BusinessCloud reported Centrica's completion of the purchase in September 2024; the price was not disclosed. ENSEK's 2025 modern slavery statement says the business is now covered by the Centrica group statement.

Acquisitions

ENSEK bought Zoa in September 2024. More than 45 Zoa staff joined, taking ENSEK to about 550 people.

People

The company reports more than 600 staff in 2026, up from five in 2014 and more than 100 in 2018 (about). Its founder still leads it as chief executive (team), and it has recently appointed new chief technology, product, marketing and revenue officers. No separate revenue or profit figures are published; results sit inside Centrica's retail business.