Employees talking on building site

How we can meet your needs:

Wholesale Operations

Our wholesale services team works closely together to keep operations running smoothly and resolve issues as quickly as possible.


The team also provides a point for escalation of issues or problems.

Account Management

It's important that we understand your needs, so we provide an account manager to handle your business with us.



  • talk through and agree contractual issues
  • manage regular liaison meetings
  • work to find the right solutions for you


Our account managers are experienced professionals with extensive knowledge of the wider water industry and Northumbrian Water.


They have expertise in a broad cross section of relevant activities, including metering, trade effluent, customer service and commercial water activity.

Wholesale Operations Service Desk

Our team of water services representatives can help with all day to day activities and enquiries from retailers.


From processing forms through to specific technical enquires, we're available Monday to Friday, from 9am to 5pm.

Property Data Integrity

We have an established team already successfully maintaining Northumbrian Water’s property data set.


This same team works within the Wholesale Services team to make sure all non-household and household property data enquiries are dealt with efficiently and effectively.


They will continue to regularly maintain and update our property data set within CMOS (Central Market Operating System) and our internal systems.

Settlement and Reconciliation

We are 'shadow billing' the CMOS system and using our own internal computer billing system to make sure settlement reports are reconciled with retailers and CMOS records.


The team are available to discuss and focus on settlement reports and any issues.


They’re also responsible for all aspects of the invoicing process for both primary and non-primary charges.


Each retailer will have three separate internal accounts with us in respect of primary charges, non-primary charges and GSS payments.


This team also monitor and action any ongoing requirements in respect of your agreed credit terms.


To achieve compliance with our Level Playing Fields, we've got a dedicated compliance officer in our team.


We can produce regular data on compliance and performance matters and are available to investigate and resolve and compliance related issues.

Where are we based?

The Wholesale Service desk, Property Data team, Settlement and Reconciliation and Compliance teams are based in Durham, in our northern operating area.


Our Account Management team is based in offices in Durham and near Chelmsford, in our southern operating area.

When can you contact us?

Our team is available Monday to Friday, from 9am to 5pm (excluding bank holidays).


Additional business hours may also be available on a required basis.


Out of office hours


You can contact our operations team at Northumbrian Water on 0345 717 1100, and our operations team at Essex & Suffolk Water on 0345 782 0999.


Other ways to contact us


If you prefer, you can email us at wholesale@nwl.co.uk.

Key information


This is the Central Market Operating System, used by MOSL to manage all electronic transactions by switching customers.


Oracle’s Customer Care and Billing Software is our retailer contact and workflow software for all retailer engagement.


The system is used to monitor our market related service level agreement performance.


It also creates shadow bills that replicate the settlement reports from CMOS which are used to compare against the retailer invoices that CC&B also produces from the aggregated settlement reports.

Data Warehouse and Bi Tool

Our corporate data warehouse and business intelligence reporting engine, which uses Oracle Utilities Analytics, is our repository for all corporate data.


This will also be used for investigating  discrepancies between the CC&B and CMOS datasets.

Operational Portal

Our operational portal is currently under development and will provide gated access to a range of published information.


This information will include:

  • planned and unplanned events
  • trade effluent sample data, and
  • general policies and procedures.


It is also hoped to utilise the standard operational message format to facilitate electronic exchange of primary instigating operational messages via web-service.

Laboratory Information System

Our laboratory information system holds all our trade effluent sample data and relevant extracts will be published on the web-site as well as being emailed to retailers.

Affinity Marketflow

Affinity Marketflow, by AMT Sybex, co-ordinates all messages between the CMOS system and our own internal systems.

Search our website