Identifying a ~£1m cost avoidance opportunity in a large supplier's customer migration

Written by Rachel Littlewood
31 Aug 2023
Transformation Re-platforming
  • Large energy supplier preparing for the background migration of its customer base to a new system provider
  • We reviewed their customer portfolio and discovered ~850k data mismatches that needed rectifying, also highlighting actions to address hidden issues, process waste, and work smarter opportunities
  • We realised a ~£150k cost saving through bulk fixes to ~35k accounts, identifying an opportunity for ~£1m in cost avoidance once all accounts have been fixed


We supported a large energy supplier with the migration of its customer base to a new system provider.

As this was a background migration, we helped the supplier to cleanse their existing customer data, ensuring that any potential risks were recognised in advance and managed effectively.

Migrating customers can be a difficult process for suppliers, having disruptive consequences if handled incorrectly. In this case, we supported our client throughout the preparation stage, which is critical to the success of any migration project.

​Our approach

We started by conducting a reconciliation of the supplier’s customer portfolio and compared our findings with industry meter data. This allowed us to produce an end-to-end view of any errors in the portfolio, highlighting the areas in which a data cleanse was required.

During our review, we discovered ~850k data mismatches that needed addressing before the migration could be attempted. These mismatches were caused by meter point discrepancies between the supplier’s internal system and the industry system, creating potential for a failed migration, or post-migration issues such as inaccurate billing.

We also found that ~250k meters were unfit for billing, due to various issues with the customer’s account or the meter itself.

When compared to electricity, the supplier’s gas portfolio had ~140% more accounts without an accurate bill in the last 12 months. Ideally, all accounts should be billed recently and accurately prior to migration, so rectifying this was a key factor in our client’s preparation.

To help mobilise this, we used our reconciliation findings and identified three categories of required improvements, covering:

  • Hidden issues – preventing disruption later in the migration
  • Waste opportunities – identifying and removing redundant tasks
  • Work smarter opportunities – enabling more efficient ways of working

Using these categories, we delivered a series of background improvements and recommendations, helping the supplier to prepare for migration with minimal disruption.


As most billing and settlement issues were caused by lower-level anomalies, we were able to make bulk fixes to ~35k customer accounts, realising a ~£150k cost saving through reduced manual work, demand, and complaints.

In addition to this, we identified a further cost avoidance benefit of ~£350k from bulk fixes across ~50k accounts, with the total benefit expected to reach ~£1m after all accounts had been fixed.

During this 12-week project, our team highlighted ~115k customer accounts that were unfit for migration, which the supplier was unaware of prior to our intervention. Addressing these issues was a key focus of our recommendations, giving our client peace of mind when proceeding with the migration.

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Jonathan Paton

Senior Manager

Jon specialises in Customer Operations leadership, customer contact, and operational service delivery transformation/improvement.

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Kev Brown


Kev leads our continuous improvement and lean transformations, working with leaders to deliver our Operational Excellence programme.

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Craig Sutherland

Senior Consultant

Craig has experience working on both large and small-scale business transformations, IT and people migration programmes, change management and leading cultural transformation.

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