Frequently asked charges questions
On this page we cover frequently asked questions relating to changes in our charges.
Why are my bills going up?
Every day, we manage billions of litres of drinking water and wastewater. We must make investments to ensure we keep this essential service flowing. This allows us to continue to invest into our infrastructure and services.
How the prices are set
We go through how we set prices for billing our customers.
Who and how are the prices set?
Our water industry regulator, Ofwat, has finished their industry-wide price review for 2024. They’ve reviewed our business plan for 2025 to 2030. A final determination has been issued. It sets the level of revenue we can recover from our customers. We’ve used this as the basis for our charges over the upcoming charging year.
All water companies have to follow Ofwat’s charging rules when setting their prices. Ofwat no longer specifically approves the charges each water company sets.
Why is Ofwat giving a lower percentage of bill rises than what Thames Water have published?
The 35% bill increase Ofwat published doesn't include the impact of inflation. It's an average of the price rises across all customers. This also includes those who may move onto our social tariff and get a discount on their bill. These average bill increases won’t reflect the actual increase to customer bills.
We're using a number that better reflects the price increase that customers will see on bills. This is known as a ‘typical’ bill increase. The increase will include inflation and cross-subsidy that pays to fund social tariff. Typical bill increases assume that the customer stays on the same tariff from one year to the next. It also assumes they don't change the amount of water usage.
Will my bill be affected by appealing to Competition and Markets Authority (CMA)
No, the price rises for 2025-26 we advised customers about will not change. The first year of the new five-year cycle 2025-2030 will carry on as planned. We have committed to achieving a lot in the first year.
When the increase will start and how much it will be
We go through when the increase will start and how much it will be for each type of customer.
When will I get my first higher bill?
Your new charges will officially start on 1 April 2025. This will depend on whether you have a meter or are unmetered.
Unmetered customers
If you don’t have a water meter, your 2025-26 bill will arrive between February and March.
Metered customers
For water meter customers, you’ll start seeing changes to your next bill from April onwards.
Payment plan customers
Your instalments may go up based on our new prices. We usually check and adjust your payments. This is in line with how much water you’ve used and what we think you’ll use for the year ahead. From April, we'll reassess your plan every six months instead. This will make sure bills are as accurate as possible and that we’re not under or overcharging you.
How much will my bill be increased?
Bills for typical water and wastewater customers will increase by £17 per month. This is on average for 2025-26. The increase could be higher or lower if your metered, unmetered or on rateable value. For assessed household customers, it will depend on number of bedrooms or if you live alone.
Why are the increases different depending on my tariff?
This is primarily because of the existing typical bill values for each tariff type. Our underlying unit rates for variable charges are increasing by the same percentage. This is across each tariff type. While our fixed charges are increasing consistently across all tariff types. Percentage increases for metered and assessed household customers is higher than for unmetered.
Are all parts of the bills (fixed charges and unit rates) going to increase in the same way?
No, different increases are applied to different parts of the bill. Our unit rates for variable charges are generally increasing by the same percentage. This across each tariff type. Though there are different rate increases for water service and for wastewater service. Fixed charges are increasing by a higher percentage than variable ‘unit rate’ charges.
The percentage increases also vary for different tariff and service types. This is so that our charges are more consistent for all customers without a meter. Find out more in our statement of significant change.
Do the new charges apply to all customers or just specific regions/plans?
The new charges will apply to everyone in our supply area.
Will bills go up again soon? Will it be increased by the same amount?
We review our prices once a year. This year, our charges will change on 1 April 2025. Ofwat set out in their final determination that prices are set to increase each year. This is for the period 2025-2030. The price rise next year is however expected to be much lower than in this year, and will be more in line with inflation.
What we will spend the money on
We go through what we will spend the money on for the increase.
Where can I find out more about what you’ll be spending the money on?
The new charges are part of our five-year business plan. It sets ambitious goals based on a record level of investment. You can view our five-year plan in progress.
What do you plan to do with the money?
Over the past few years, we’ve done everything we can to avoid increasing our prices. We will invest the money customers pay to us to improve in the areas they have told us matter most to them.
- Keep safe, high-quality drinking water flowing with fewer interruptions
- Fix leaky pipes and the aging mains network to reduce wasted water
- Invest in upgrading our sewage works
- Reduce pollution incidents and storm overflows
- Ready the water network for population growth and climate change
The changes we're making are part of our five-year plan. This sets out our ambitious goals to invest in and improve services for you.
We also have a range of projects that are helping to transform our network and protect the planet.
Are you going to improve the health and water quality of our rivers?
We’ve set goals to reduce pollution in our five-year plan. The plan is still under review, but we’re currently aiming for a 30% drop in pollution incidents by 2030.
Our targets will be confirmed after this current price review. But no matter what happens, reducing pollution will be a huge priority for us moving forwards. We know we must do more to look after our rivers and streams. We’re determined to reduce pollution, storm overflows and blockages. You can view our five-year plan in progress.
Am I paying for the company's mismanagement, bonuses, debt and, dividends?
That’s not the case. We have not paid an external dividend since 2017. We have committed to pay no external dividends before 2030. We are maximising investment in updating our critical assets. Ofwat has ruled executive bonuses cannot be paid from money collected from customers. This is unless our performance meets expectations.
Are customers paying the cost to improve Thames Water's financial position?
This speculation is untrue and misleading. The £3 billion liquidity extension will not impact our proposed increase of bills. This includes for the next five years
The debt extension is a interim funding solution whilst we stabilise the business. This is with the aim to delivering an investable and financeable business plan. This liquidity extension provides us with the ability to continue to further invest.
How will I know that my money is being spent on the things you say?
We always endeavour to keep our customers updated with the investments we’re making. We'll do this through our website, in customer comms, and to the media. The water sector is also highly regulated. Ofwat and the Environment Agency monitor the activities of all water companies in the UK.
Water companies not performing in line with targets set by Ofwat, will face penalties. This would reduce the revenue that the water company can recover from its customers.
Why was the Final Determination sent to Competition and Markets Authority (CMA)?
The Thames Water Board has made the decision to refer Thame Water’s Final Determination to the CMA. This is in the best interests of customers, the environment and business operations.
The decision was not made lightly. We need to enter the next regulatory period on a stronger footing. This will help support growth, customers, the environment and adapt to climate change.
I have received an email/letter from Thames Water about price changes. Is it legit?
We’re contacting customers by email or letter to make sure the following is communicated:
- Why our prices are changing and when
- Where that money will be invested
- How we can help if you’re worried about affording your bill
What support can you give me?
We’re already helping around 450,000 customers pay their bills. We’re here to help find the best solution for you. You can view all the support schemes we offer on our financial support page.
Can I switch to a cheaper tariff or plan to avoid a higher bill?
If you don’t have a water meter yet, using one could help you take better control of your bill. With a water meter, you can track and pay for exactly how much water you use. In some cases, it can help you save money. This is dependent on if we're able to fit a meter at your property.