Check your previous bill or meter reading. Small offices use approx 50-100 m³.
Avg ~£1.50 – £1.80
Avg ~£1.60 – £1.90
Based on meter size
Surface/Highways
Usually 90% or 95%
Estimated Annual Costs
Water Volumetric Cost:£0.00
Sewerage Volumetric Cost:£0.00
Total Fixed Charges:£0.00
Total Annual Cost (ex VAT):£0.00
Estimated Monthly Direct Debit:£0.00
Guide to Business Water Rates in the UK
Understanding commercial water bills in the United Kingdom can be complex due to the deregulated water market. Since 2017, most businesses in England have been able to switch their water retailer, similar to gas and electricity. This guide explains how your bill is calculated and what the inputs in the calculator above represent.
Components of Your Water Bill
Your business water bill is generally split into two main categories: Wholesale Charges and Retail Charges. The calculator above focuses on the total cost, breaking it down into the core measurable components:
1. Volumetric Charges (Usage)
This is the cost for the actual water you use, measured in cubic meters (m³). One cubic meter equals 1,000 litres.
Potable Water Rate: The price per m³ for clean water supplied to your taps.
Sewerage Rate: The price per m³ for the waste water taken away from your property.
2. Standing (Fixed) Charges
Regardless of how much water you use, you will pay fixed charges based on the size of your water meter (e.g., 15mm, 25mm, 50mm) and the Rateable Value (RV) of your premises. These cover the cost of maintaining the infrastructure, reading meters, and customer service.
3. Return to Sewer Allowance
Water companies assume that not all the water you buy returns to the sewer (some is consumed, evaporated, or used in products). The standard assumption is usually 95% or 90%. If your business uses significant water for irrigation or production that isn't discharged, you can apply for a lower "Return to Sewer" percentage to reduce your sewerage bill.
4. Surface Water and Highway Drainage
This is a charge for rainwater draining from your property (roofs, car parks) into the public sewer. It is often a fixed annual fee or calculated based on the site area of your business premises.
How to Lower Your Business Water Rates
Did you know? In Scotland, the business water market has been deregulated since 2008, while in England it opened in 2017. Wales remains largely regulated.
To reduce your business water costs:
Switch Retailers: Compare quotes from different licensed providers to find lower retail margins.
Water Audit: Check for leaks. A dripping tap or running toilet can waste hundreds of cubic meters a year.
Consolidated Billing: If you have multiple sites, combining them into one contract can reduce administration fees.
Verify Fixed Charges: Ensure you are not being charged for Surface Water Drainage if your water drains into a soakaway or local watercourse.
Using the Calculator
To get the most accurate estimate from our Business Water Rates Calculator:
Locate your Supply Point Identifier (SPID) on a recent bill to confirm your meter details.
Input your annual consumption in cubic meters (m³). If you only have litre usage, divide by 1,000.
Adjust the unit rates based on your specific region (e.g., Thames Water, Severn Trent, United Utilities areas differ in wholesale costs).
function calculateWaterRates() {
// 1. Get Input Values
var usage = parseFloat(document.getElementById('annualUsage').value);
var waterRate = parseFloat(document.getElementById('waterRate').value);
var sewerRate = parseFloat(document.getElementById('sewerRate').value);
var fixedWater = parseFloat(document.getElementById('standingChargeWater').value);
var fixedSewer = parseFloat(document.getElementById('standingChargeSewer').value);
var drainage = parseFloat(document.getElementById('drainageCharge').value);
var rtsPercent = parseFloat(document.getElementById('rts').value);
// 2. Validate Inputs
if (isNaN(usage) || usage < 0) {
alert("Please enter a valid Annual Water Usage.");
return;
}
if (isNaN(waterRate) || isNaN(sewerRate) || isNaN(fixedWater) || isNaN(fixedSewer) || isNaN(drainage) || isNaN(rtsPercent)) {
alert("Please ensure all rate and charge fields contain valid numbers.");
return;
}
// 3. Perform Calculations
// Water Volumetric Cost
var waterVolCost = usage * waterRate;
// Sewerage Volumetric Cost
// Logic: Usage * (Return to Sewer % / 100) * Sewer Rate
var returnToSewerDecimal = rtsPercent / 100;
var sewerVolCost = usage * returnToSewerDecimal * sewerRate;
// Total Fixed Costs
var totalFixedCost = fixedWater + fixedSewer + drainage;
// Total Annual Cost
var totalAnnualCost = waterVolCost + sewerVolCost + totalFixedCost;
// Monthly Cost
var monthlyCost = totalAnnualCost / 12;
// 4. Update UI
document.getElementById('resWaterVol').innerHTML = "£" + waterVolCost.toFixed(2);
document.getElementById('resSewerVol').innerHTML = "£" + sewerVolCost.toFixed(2);
document.getElementById('resFixed').innerHTML = "£" + totalFixedCost.toFixed(2);
document.getElementById('resTotalAnnual').innerHTML = "£" + totalAnnualCost.toFixed(2);
document.getElementById('resMonthly').innerHTML = "£" + monthlyCost.toFixed(2);
// Show results area
document.getElementById('results-area').style.display = "block";
}