Holistic Wholesaler Tables

To find out more about the measures used in these tables, click the 'Wholesaler Measures' link on the right.

Colours on these charts are assigned based on quartiles (light blue representing the highest performing quartile; dark blue representing the lowest).

The tables were updated in September 2025

The reporting periods for the information in the below tables are as follows: 

  • Reporting period for wholesalers - August 2025
  • MPS reporting Period - May 2025 to July 2025
  • R-MeX reporting period - February 2025

Wholesalers with more than 10,000 supply points

more than wholesaler

Wholesalers with fewer than 10,000 supply points and NAV wholesalers

less than wholesaler

Wholesaler measures

M12 - Premises with verified supply address and premises and data score

This area summarises the number of premises with verified supply address and premises data. A higher score indicates a higher number of premises within a wholesalers area that have a verified supply address, verified UPRN and verified VOA BA Reference.

Why is it important? Accurate premises and supply address data allows a retailer to more easily compete meter reading activites, manage occupancy effectively and provide accurate customer data..

M15 - Average lateness of Bilateral SLA score

The average number of days late past Bilateral Service Request SLAs that the wholesaler has completed the requests in the previous calendar month. A lower score in this area is better; whilst the SLA was completed late, the wholesaler has fewer average days late. No score in this area indicates that no SLAs within the reporting period have been completed late. Only MPF affecting SLAs are counted in this metric.

Why is it important? Timely completion of SLAs is important and where late, it is useful to understand how late the SLAs are. M15 incentivises a wholesaler to work to complete Bilateral Service Request SLAs in a timely manner or minimise their level of lateness.

M18 - Bilateral Tasks completed in month completed on time score

The number of Bilateral Service Request SLAs which are completed on-time within the reporting window; the previous calendar month. A higher score in this measure indicates a higher number of SLAs completed on time. A lower score indicates lower levels of on-time completion. Only MPF-affecting SLAs are counted in this metric.

Why is it important? Timely completion of SLAs is important. M18 incentivises a wholesaler to work to complete Bilateral Service Request SLAs in a timely manner.

Market Performance Standard (MPS) 

This area summarises the wholesaler’s abilities to read meters where this is their responsibility, and to complete new supply connection information within the prescribed timeframes. 100 per cent performance in this area would indicate that the wholesaler has read all applicable meters and completed all new connection activities e.g. all meters that have been replaced during that month have received a final meter reading.

Why is it important? Timely creation of new supply connections and timely and accurate meter reads are key to providing the customer with the correct bill. These are recognised as key processes affecting customer outcomes as they introduce new customers to the retail market and impact timely and accurate billing.

Geographic Information System (GIS) Score

A GIS score is a framework for gathering, managing, and analysing location data. The API is calculated as the percentage of meters that present with credible GIS data on CMOS as a percentage of all meters managed by the wholesaler. Poor performance in this measure highlights GIS coordinates that are potentially inaccurate/erroneous. 100 per cent performance in this area would mean that all meters show no indication of potentially erroneous GIS data. Discretion must be exercised with this API as, although a number of meters present at a single set of co-ordinates may be indicative of imprecise and arbitrary assignment of GIS data, it equally might be representative of a grouping of meters which serve multiple customers in a single premises (e.g. in the basement of an office block).

Why is it important? GIS helps identify the meter location which supports retailers in successfully reading meters and provides for accurate settlement of primary charges and customer billing based on meter reads.

Long Term Vacant (LTV) Score

A premises is defined as LTV when it has been vacant for six consecutive years and there has been no consumption identified. 100 per cent performance in this area would mean that none of a wholesaler’s premises have been vacant for that length of time. There may be valid reasons why a wholesaler cannot take a LTV premises out of the market, especially if the managing agent of that premises has intentions to redevelop/ re-occupy it and therefore a score of 100 per cent may not be possible.

Why is it important?  Reduction of LTV helps identify customers and provides more accurate data on supply points in the market including identification of premises that should no longer be in the market.

Legacy Long Unread Meter (LLUM) Score

A LLUM is a meter which has not been read since the market opened in 2017. The LLUM percentage is calculated as the number of LLUM meters, within both vacant and occupied premises, as a percentage of all meters managed by the wholesaler. 100 per cent performance in this area would mean that all of the wholesalers’ meters have been read at least once since market opening.

Why is it important? The measurement of LLUMs supports accurate customer billing and accurate settlement and places focus on those meters with an aging read history.

Wholesale Long Unread Meter Score

A Wholesaler Long Unread Meter (WLUM) is defined as a Long Unread Meter (LUM) against which an open bilateral Operational Request ID (ORID) for a meter verification or repair is outstanding. Once the ORID is closed the WLUM is returned to the retailer’s list of LUMs. Once the retailer reads the meter (or enters the W Read which may have been supplied by the wholesaler on completion of the request) then it will be removed from the retailer’s LUM list. The holistic reports therefore represent the number of WLUMs recorded against a wholesaler as a percentage of all tradeable water SPIDs recorded against the wholesaler, and then multiplies that figure by the average number of days since those WLUMs were last read to determine wholesaler rankings. A WLUM which has been deferred will be returned to the retailer’s list of LUMs and will not be counted in this metric​

Why is it important? This Additional Performance Indicator aims to keep the focus on resolving the WLUMs, even if the wholesaler has comparatively few WLUMs recorded against it.

Retailer Measure of Experience (R-MeX) Score

The R-MeX is a biannual survey which provides a quantitative, as well as qualitative, measurement of wholesaler service. Retailers are asked to score wholesalers in six key areas: responsiveness; communication; data quality; systems and notifications; engagement; and financial policies. High performance in this area would indicate that a strong working relationship exists between a wholesaler and a retailer which would underpin positive customer outcomes.

Why is it important? Customers do not typically have a direct relationship with the incumbent wholesaler. Customers are reliant on their retailer to represent their interests in areas such as locating or repairing meters or handling complaints and strong R-MeX scores give the customers confidence that such requirements are likely to be managed efficiently.

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