In our latest blog post, Castle Water CEO John Reynolds explains why submitting two meter reads one month apart will help reduce your water bill after you re-open your business.

When you re-open your business, Castle Water can help make sure your water bills are correct. Water charges are calculated based on your meter reading history, in line with the way charges are calculated in the water market central systems known as CMOS). Your water usage will probably be lower when you re-open, due to reduced staff, fewer customers, or a reduced range of services. You can help us make sure charges are correct by sending us two meter readings one month apart (eg on 20 July and 20 August). This will enable our own systems, and CMOS, to calculate your usage based on your new level of activity, and not on pre-Covid levels.

You can send us a meter reading at any time at which also allows you to upload a photograph of the meter.

When you re-open, for customers who pay 6-monthly, we will send you the first bill for a short period of time, usually 4 months. Sending us two initial meter reads means that your next bill will then be produced on your revised and up-to-date usage.

With around half of our customers re-opening premises in a short time-frame, we can’t realistically get around and read all the meters ourselves. I can reassure you that we are fully committed to reading meters, and have been active throughout June – we have taken 34,670 meters readings in June alone, and have also installed a further 410 Automatic Meter Readers.

When you submit your own meter reading and we use it for billing, we will donate £1 to Save the Children.

save the children

Ofwat and MOSL’s Requirements

Further changes as of 30 June

We are required to follow the guidelines published by MOSLon on how charges are calculated for the lockdown period. Ofwat and the water market operator, MOSL, require us to ensure that all customers who remained fully or partially open (defined as consuming more than 5% of their normal water usage) pay both metered and fixed charges. We argued against this change – the previous guidelines allowed customers with a 95% reduction in activity to be exempt from water charges. However, Ofwat and MOSL are adamant that customers should be charged for all water usage.

The following examples of water usage have been given by MOSL as an indication that customers should be paying charges:

  • Shared supplies
  • Flushing for health and safety reasons
  • Irrigation
  • Refurbishment
  • Livestock or Zoos
  • Nurseries & Garden centres
  • Partial trading (takeaway services)
  • Accommodation for Key workers

We are also required to update billing to reflect any information given to us by Wholesalers (such as Thames Water) which indicates that businesses continued to operate. The guidelines state: Wholesalers may well have easier access to better evidence on actual consumption at particular supply points than is currently reasonably available to Retailers. This could include for example data from Wholesaler field visits; AMR reads; smart meters; and dataloggers. Retailers are expected to use this evidence in a timely way to remove Vacancy flags or restore Yearly Volume Estimates necessary.

Where there has been water usage in a Vacant site, we are required to invoice for the period of the vacancy. The guidelines state: Where the temporary vacancy flag has been applied differently to the illustrative examples below, it is expected that retailers will reverse the flag from the original date. It is recognised that this may cause challenging conversations with customers and potentially complaints where a premises has in good faith been previously assessed as vacant.

Ofwat and MOSL may change this guidance in the future, and customers should be aware that charges may therefore be subject to review. Castle Water has argued that retrospective changes to charging are unhelpful to our customers, in some cases causing financial distress, but Ofwat and MOSL have not accepted this argument.


More information on water meters and meter reading

Who owns the meter

Your water meter is owned by your water Wholesaler, which is different from the market arrangements used in electricity or gas. You are responsible for the water supply from the meter into your property; the Wholesaler is responsible for the supply up to and including the meter. Only the Wholesaler or specialist accredited contractors are permitted to replace or maintain the meter or the public water network.

Who can take a meter reading

Both the Retailer and Wholesaler are able to enter meter reads into the central market systems (CMOS). The customer can also take meter readings, which have to be passed to the Retailer for use in billing and to be entered into the market systems. Meter readings are recorded centrally so that Wholesale charges can be calculated accurately and your water usage is available to other retailers if you decide to switch. Customers who rely on meter readings to monitor their consumption can take readings at any time – although we would advise that water meters are not designed to monitor consumption for leaks and are not a substitute for appropriate maintenance.

Castle Water uses a range of specialist contractors to manage our meter reading services, including Thames Water and Portsmouth Water. We supplement this with our own meter reading team, which carries specialist equipment and is often used to read difficult-to-access meters.

Regular meter readings

Castle Water tries to take meter readings at least twice a year. Unfortunately, this isn’t always possible – for example, if the meter is inside your property and you have access restrictions, or if there are vehicles regularly parked over the meter pit, for example, some streets in London have on-street parking which is used every day, and which covers meter pits. If we have not been able to take a meter reading, you can send us a meter reading which we will use to calculate your bill. If we have not been able to take a meter reading and you haven’t provided a reading, you will be liable for charges based on our estimate of your usage.

For some customers, usage can fluctuate significantly – for example at farms. The market Codes don’t take this into account when they calculate Wholesale charges. The bills we send you will estimate usage based on the pattern of recent usage, the same approach as used in the central market. If your usage reduces, this will be reflected in your next bill after your meter readings show the drop in usage. You can set up a monthly direct debit to spread payments evenly across the year, which helps avoid seasonal peaks in payments.

Repairs and maintenance of the meter

Under the Codes (in Section 4 of the Business Terms) which govern the water market, the Wholesaler is responsible for the maintenance and repair of the meter, and for recording the relevant information to ensure you are charged correctly. This includes the meter number, its size, and its location. If you identify a problem with the meter itself, you should notify Castle Water and we will ask the Wholesaler to inspect the meter. If the Wholesaler carries out a visit and there is no fault, you will be liable for a charge. If you request a meter accuracy test, the Wholesaler will normally remove the meter and test it offsite. You will be liable for a charge (which can be significant) if you request a meter accuracy test and no fault is found with the meter.

You can notify us of any issues with the meter at and upload a photo of the meter you are reporting.

If the meter pit is on public land, and it is seriously obstructed, contact us and we will ask the Wholesaler to either move the obstruction or move the meter – typical obstructions would include being covered under a relaid pavement.

There are SLAs in the Codes governing the time allowed to a Wholesaler to carry out inspections, tests, and repairs, typically of 20 business days. However, the SLAs are not always met, and Castle Water does not have any specific enforcement role in this regard.

The Wholesaler does not normally need to carry out repairs if:

  • The meter pit lid is stuck
  • There is water in the meter pit
  • There is something obscuring the glass
  • There is a minor obstacle obstructing access to the meter (eg, a build-up of dirt)
  • In these cases, the Retailer or the customer can carry out the basic maintenance required to use the meter.

Safe location

The Wholesaler has an obligation to ensure that the meter is in a location where readings can be taken safely. Where the meter is in an unsafe location, Castle Water can request the Wholesaler to relocate the meter. Examples of an unsafe location would include a meter being located on a busy road. Where a meter is in an unsafe location, we may be unable to read the meter until it is relocated by the Wholesaler.

Data-loggers / AMR

Castle Water frequently fits Automatic Meter Reading (AMR) equipment to high-volume water supplies (normally meters of 80mm or above). This will give continuous readings, and is useful to monitor water usage for industrial processes, or in case of a leak.

If there is an AMR this may be the property of the Wholesaler, the Retailer, or the customer, any of which can install AMR. The party which owns the AMR will be responsible for its maintenance. Installing AMR is straightforward and does not require any interruption to the water supply.

Where we fit AMR we are unable to provide a guarantee that we will identify leakage, and this should not be a substitute for maintenance of your plumbing or water network and connected appliances.

The meter number on my invoice is different from the meter supplying water to my property

Our invoices show the usage for each meter you have and identify the serial number of the meter. The serial number will also be on the meter itself. Occasionally we find that the Wholesaler has registered an incorrect meter number, or has not recorded a changed meter. If you think this has happened, please take a photo of the meter and send it to us, and we will ask the Wholesaler to update the central market records. You can report this at

Maintaining access

If the meter is on public land, maintenance and repair of the meter pit will be the Wholesaler’s responsibility. Where the meter is on the customer’s land, the customer should ensure the meter pit is kept clear and is accessible.

How meter readings are used

For most customers, Castle Water uses meter readings in line with the way charges are calculated by the central market systems: we take the most recent reads and calculate an Average Daily Charge (ADC). The ADC, which is shown on your bill, is used to calculate charges for each day of the billing period covered by the invoice. Where you provide an up-to-date meter reading, we will use this to calculate your next bill.

Other services

Castle Water can offer a range of services to help you manage your water consumption, including:


Tips from Castle Water’s meter readers

Our meter readers can offer some simple tips which can make it easier to read your own meter:

  • If there is water in the meter pit, it isn’t normally a sign of a leak. You can pump out water with a hand-operated pump, and a bicycle pump can normally do the trick if you don’t have a pump.
  • You don’t need to get close enough to read the meter – just hold your phone over the top of the pit and take a photo.
  • If there is some mist or dirt on top of the glass, tie a sponge to a pole (or broom handle) and gently wipe it.
  • If the meter pit cover seems stuck, you can normally free it with a screwdriver or small pry bar.