Thames Water meter — compulsory rollout, smart meters, readings & savings

Thames Water meter rollout: where it stands today

Thames Water is in the middle of a compulsory smart-meter rollout, not a finished one. Around 2 million homes in its supply area are already metered and the company has committed to reaching most of its ~15 million customers by 2030. The programme has been authorised since 2019 because the region is officially classed as water-stressed, a status given by the Environment Agency that lets a water company impose meters without customer consent.

In practice, the rollout follows a postcode-by-postcode schedule rather than a single switch-on date. Thames Water writes to households when their street is next in line, fits the meter, and then runs a 12-month comparison period (see below) before the metered tariff replaces the old rateable-value bill. New installations are exclusively smart meters, which transmit a reading hourly over the airwave network, so no manual reading is required.

If you have an older "classic" meter installed before the programme started, Thames Water is gradually replacing those units with smart ones too. In the meantime, send a reading at least twice a year through your online account or the dedicated reading line to avoid estimated bills. For the full picture of how Thames Water operates — contact numbers, bills, complaints and the 2025 Ofwat fine — see our Thames Water supplier overview.

Metered or unmetered bill: how Thames Water charges today

Until a meter is fitted, Thames Water bills you on the property's rateable value — a fixed annual charge that takes no account of how much water you use. Rateable value is the way council rates were calculated before 1990 and water companies have kept it as their fallback billing method. Once a meter is fitted and the 12-month comparison period ends, the unmetered tariff disappears and your bill is based on the volume of water actually drawn, plus a small standing charge.

The two systems can produce very different bills for very similar households. A single occupier in a four-bedroom house typically pays far less on a meter than on a rateable-value bill, because the rateable value reflects the size and value of the property rather than how many people live in it. A family of five in a small home is the inverse case: high water use, low rateable value, and a metered bill that may be higher than the unmetered one. The 12-month comparison period is specifically designed to surface this difference before the switch becomes permanent.

Source: Thames Water charges scheme and Defra guidance on metering options. As a rule of thumb, homes with fewer occupants than bedrooms usually save on a meter.

Request a free meter without waiting for the rollout

You do not have to wait for your street's turn in the rollout — any Thames Water customer can request a free meter at any time. Installation is carried out at no charge under the Water Industry Act, and over 2 million Thames Water households have already been fitted. The fastest route is to submit the request through your Thames Water online account or by calling 0800 980 8800; a self-service installation date is normally offered within a few weeks.

The visit itself is short — typically 45 minutes from arrival to leaving, with the water supply turned off for around 30 minutes while the engineer fits the meter. Wherever possible Thames Water prefers to fit the unit outside the property, under a small round cover on the public footpath, the drive or the front garden; an internal location near the main stop-tap is used only when the boundary fitting is impossible.

If you are a tenant, permission from the landlord is not legally required for an installation under the compulsory metering programme. Notify your landlord or letting agent as a matter of courtesy, especially if internal access is needed — but they cannot prevent the meter being fitted. For more on water billing as a renter, see our set up a water bill guide.

Free Smarter Home Visits

Once a meter is fitted, Thames Water offers a free Smarter Home Visit in which an engineer comes to the property, identifies where water is being wasted and fits free water-saving devices — typically tap aerators, shower regulators, cistern bags and dye tablets to check for silent toilet leaks. It is one of the quickest ways to bring a metered bill down without changing daily habits radically, and the visit itself takes around an hour.

Can I refuse a Thames Water meter or switch back?

You cannot refuse a Thames Water meter on principle, and once it is fitted you cannot switch back to a rateable-value bill — but you can stay on your old unmetered tariff for a full 12 months while you decide. This is the single biggest difference between Thames Water and most other UK suppliers, where customers can request a meter trial and revert to the rateable-value bill within 24 months if it works out more expensive.

If you refuse to let installers inside to fit an internal meter, Thames Water will normally place the meter externally at the boundary instead. If both options are impossible, the household is moved onto an assessed or "no access" tariff, which is deliberately set higher than the typical metered bill to encourage cooperation. In almost every case, accepting the install is cheaper and simpler than holding out.

The 12-month comparison period in detail

After the meter is fitted, Thames Water keeps you on the old unmetered tariff for 12 months and runs a parallel calculation showing what your bill would have been on the metered tariff. The company sends comparison letters at three, six and ten months so you can see the running difference and decide when to switch — or wait until month 12 and be moved across automatically.

How to read your Thames Water meter

Record only the black digits on the dial and ignore the red ones, which measure fractions of a cubic metre and are not used for billing. Most Thames Water meters show a row of five black digits followed by three or four red digits or a single red dial; the black figure is the cubic-metre total since the meter was first installed. You do not need to enter any decimal point — Thames Water adds it automatically when calculating your usage.

If you have a smart meter, no manual reading is required: the unit sends a reading every hour over Thames Water's airwave network and your online account shows daily and weekly charts of consumption. Smart-meter users only need to look at the dial if they suspect a fault or want to cross-check what the supplier is recording.

With a classic meter, Thames Water aims to send an inspector twice a year, but readings in between are your responsibility if you want to avoid estimated bills. Take a reading on a fixed day each quarter — pay-day, the first Saturday of the month, whatever you will remember — and submit it the same evening through the channels listed below. For a step-by-step walk-through with photos, see our how to read a water meter guide.

Three ways to submit a meter reading

All three submission channels are free and take less than a minute once you have your account number to hand. Choose the one that matches how you prefer to manage your bills.

Smart meters: hourly readings, leak alerts and lower bills

Thames Water's new smart meters transmit a reading every hour over the airwave network, which removes estimated bills and gives near real-time data on how much water each household is using. The granular data turns up problems that classic meters cannot — overnight leaks, a dripping toilet cistern, or a hose left running — and feeds into the leak-alert system described below.

Households on a metered tariff can typically cut their bill by 10–15% in the first year just by acting on consumption charts: shorter showers, turning the tap off while brushing teeth, and fixing dripping fittings. The Smarter Home Visit and free water-saving devices push that figure further. Because smart-meter data is updated daily in the online account, you can see the effect of behaviour changes within a week rather than waiting for a quarterly bill.

Continuous-flow leak alerts

Smart meters automatically flag continuous flow — water running through the meter for hours at a time when nobody is at home — and Thames Water emails or texts the account holder with a leak warning. Underground supply-pipe leaks between the boundary meter and the property are the single biggest hidden cost for metered customers, and catching them early can save hundreds of pounds in a single billing cycle.

If you receive a leak alert, first check inside the property — running toilets and dripping outdoor taps are the usual culprits. If the alert persists with all internal stop-taps closed, call the free 24/7 leakline on 0800 714 614 to arrange an inspection. Thames Water repairs leaks on its own pipework at no charge and offers a one-off leak allowance for the higher-than-normal consumption recorded during the leak.

How to find your Thames Water meter

Most Thames Water meters sit outside the property, under a small round or rectangular plastic cover close to the public footpath, on the drive or in the front garden. Lifting the cover normally reveals a vertical chamber with the meter dial at the bottom — clean any debris off the glass with a cloth before taking a reading. In older homes the meter may be fitted inside instead, usually near the main stop-tap under the kitchen sink or in a downstairs cupboard.

If you are unsure whether your home is metered at all, check the most recent bill: a measured tariff always shows a meter reading and a cubic-metre total, whereas an unmetered bill refers to the property's rateable value with no consumption figures. When in doubt, call 0800 980 8800 and a customer-services agent will tell you which tariff you are on and where your meter is fitted.

Will my bill go up after the meter is fitted?

For most one- and two-person households a metered bill is lower than the unmetered one, sometimes by several hundred pounds a year. Larger households of three or more in a home with a low rateable value are the main exception: they were paying very little under the old rules and a meter can push the bill up. The 12-month comparison period is designed to give you a year of clear data before the change becomes irreversible.

If a metered bill turns out to be unaffordable, Thames Water runs three assistance schemes that should be your first call rather than letting arrears build up. They are all means-tested or condition-based, and the savings can be substantial — WaterSure in particular caps the entire annual bill at the regional average for eligible customers. For the wider UK picture, see our average UK water bill comparison.

WaterSure cap for eligible metered customers

The WaterSure scheme caps the bill of eligible metered customers at the average Thames Water annual charge, no matter how much water they use. To qualify you must be on a metered tariff, receive a means-tested benefit (Universal Credit, Pension Credit, Housing Benefit and similar), and either have three or more children under 19 living at home or a medical condition that requires increased water use — examples include kidney disease requiring dialysis at home, eczema and Crohn's disease.

Priority Services Register

Customers with disabilities, serious medical conditions, mental-health needs, sensory impairments, dementia, recent life-changing events, children under five, or pension-age status can register on the free Priority Services Register by calling 0800 009 3652. The flag stays on the account and triggers extra support during outages, meter installations and complex billing queries — for example bottled-water delivery if the supply fails, or an extra meter reading by an inspector if you cannot lift the cover yourself.

Faulty meter readings and inflated bills

A jammed or broken meter can produce a sudden, unexplained jump in consumption and a surprise bill. If your usage spikes without a matching change in household habits, call 0800 980 8800 and request an inspection — Thames Water will check the meter free of charge and, if it is faulty, replace it and re-bill the affected period using historic averages. If you are unhappy with how Thames Water handles a meter complaint, you can escalate it for free to the Consumer Council for Water (CCW); Ofwat only investigates company-wide failures, not individual disputes.

Thames Water meter FAQ

Useful Thames Water and water-meter guides

If you need to go further than the meter itself — phoning Thames Water, moving home, paying a bill, or understanding how UK water charges compare — our other Thames Water guides cover the supplier end-to-end. If you have just moved into the region and are not sure whether Thames Water is your supplier at all, start with the suppliers hub.

• Thames Water supplier overview — supply area, contact numbers, bills and complaints ;
• Thames Water contact number — full phone, email and escalation list ;
• Moving home with Thames Water — notice period, final reading and refunds ;
• Pay your Thames Water bill — Direct Debit, card, Post Office and Payment Card ;
• How to read a water meter — step-by-step for classic and smart meters ;
• All UK water suppliers — find who supplies your postcode ;
• UK water bills explained — average costs, metering and how charges are set.