Merger FAQs

Customer FAQs for the merger between Castle Water and Affinity for Business.

What has happened?

Castle Water has merged with Affinity for Business who currently supply water and wastewater services to 50,000 business customers throughout the UK. As a customer, you do not need to do anything.

Will my bill change now?

There will be no change to your water charges.

Who is Castle Water?

Castle Water is a leading UK business water retailer and has already successfully taken over the provision of retail services to over 350,000 customers in England. Castle Water has expertise in account management and in providing retail services tailored for business customers. Castle Water operates all customer services from within the United Kingdom. You can visit to find out more.

Why has Castle Water merged with Affinity for Business?

Castle Water has the scale and experience to build on the progress Affinity for Business has made and can offer a wide range of services including an online self-serve customer portal, free water efficiency advice as well as a variety of additional water management services such as leak detection and Automatic Meter Reading (AMR). Both companies are working closely together to ensure a smooth transition and continuity of service for customers.

Will the level of service customers receive change?

Castle Water and Affinity for Business share a high standard of customer service as shown by the very similar high ratings of customer service on Trustpilot.

What are retail services?

Retail services include meter reading, billing, customer service, collection and account management. Castle Water will provide all of these services to you going forward.

How was I notified about this change?

Customers were sent a joint (postal) letter from Affinity for Business and Castle Water informing them about the merger taking place on 1 April 2020. Customers will also receive a welcome letter from Castle Water very soon, outlining key information. If you would like to update your contact information, please call us on 01250 718700, email us at or use our webchat service at

Will my water wholesaler stay the same?

Your existing wholesale services are unchanged, and your water network owner will continue to provide wholesale services after 31st March including:

  • Maintaining the water network
  • Managing the physical supply of water to a business
  • Treating wastewater and returning it to the environment
  • Wholesale services and prices are regulated by Ofwat.

When did the merger between Castle Water and Affinity for Business happen?

The merger took place on 1st April 2020.

Do I need to do anything?

No. You do not need to take any action on receiving this update about your service.

Will my bills go up?

Your charges will not change as a result of the merger. The price you pay for water and waste services will be no higher than the default charges set by Ofwat. You can view the relevant Scheme of Charges at:

What happens to my Direct Debit arrangement?

If you currently pay for your bills via Direct Debit, you don’t need to do anything.

If I pay by online banking, BACS or standing order, what happens to my payments?

You should continue to make payments to Affinity for Business for any bills issued by Affinity for Business up to and including 31 March 2020.

Payments for bills issued by Castle Water from 1st April 2020 should be paid into the account noted below:
Account number: 14285168
Sort code: 30-80-12

If you pay digitally, please amend the payment details to these on your online banking platform.

What happens if I pay by cheque using the giro slip on my bill. Will I still be able to do this?

No. There will be no giro pay-in slip on bills sent by Castle Water from 1st April 2020 as Castle Water only supplies non-household customers. Castle Water bills will include a pre-paid envelope, so customers can post their cheque payments to Castle Water free of charge. Remember to write your account number and postcode on the back of your cheque so that your account can be credited in a timely manner.

Can I still use my Affinity for Business online account?

Yes, you will still be able to use your E-Billing account, however it will be read only. If you used Affinity for Business’s online portal, Castle Water will create an account for you on their own portal in due course so that you can still continue to manage your account online. Castle Water will contact you with your new sign-in details.

I have a signed contract with Affinity for Business. What happens now?

Your contract will not change.

Who should I call if I have a water quality issue?

For issues relating to the quality of water, if you have a water outage or a problem with wastewater, you should call Castle Water on 01250 718700 directly. We’re open from 8am – 6pm, Mon – Fri. Outside normal office hours, in an emergency, you can contact your water network owner directly. Emergency contact information can be found at

Who do I call if I have a billing query?

For questions relating to bills or your account after 1 April 2020, you should contact Castle Water on 
01250 718700 or at Castle Water’s Customer Services are open Monday to Friday from 8am – 6pm.

Does the merger affect Affinity Water (domestic) customers?

No. Affinity Water is retaining all of its household customers. The merger only relates to non-household customers served by Affinity for Business.

Can I choose to switch water and wastewater supplier?

Yes, you can switch supplier at any time however, with Castle Water customers can benefit from a high standard of customer service and our expertise in market-leading systems. To find out more about switching, visit Customers will be required to pay any outstanding charges before switching.

Who owns Castle Water?

The beneficial owners of Castle Water are two of its directors, John Reynolds and Graham Edwards. John and Graham are long-term investors who have been directors of Castle Water since 2014 and have given Castle Water the backing and stability to grow in the UK water market.

How many people are employed by Castle Water?Castle Water has over 400 employees located at the company’s headquarters in Blairgowrie and regional offices in London, Leeds, Ayr and Portsmouth.