What Changed Between 2025 and 2026?
Every April, Portsmouth Water and Southern Water update their tariffs. We've analysed the complete pricing data for both years to understand exactly how bills are changing—and who benefits.
The short version: the gap between metered and unmetered is widening. If switching to a meter made sense for you in 2025, it makes even more sense in 2026. And if you were on the fence, this might be the year to make the switch.
Unmetered Bills: Small Increases, But They Add Up
If you're on an unmetered supply (billed by rateable value), your bill is going up. But the increase isn't uniform—lower rateable value properties are seeing the biggest percentage increases.
| Rateable Value | 2025 Total | 2026 Total | Change | % Change |
|---|---|---|---|---|
| £100 | £453.78 | £463.68 | +£9.90 | +2.18% |
| £200 | £718.69 | £727.10 | +£8.41 | +1.17% |
| £300 | £1,006.82 | £1,013.31 | +£6.49 | +0.64% |
| £400 | £1,294.95 | £1,299.52 | +£4.57 | +0.35% |
| £500 | £1,583.08 | £1,585.73 | +£2.65 | +0.17% |
| £600 | £1,871.21 | £1,871.94 | +£0.73 | +0.04% |
Notice the pattern? The increases are regressive—properties with lower rateable values see larger percentage increases. A property at RV 100 sees a 2.18% increase, while a property at RV 600 sees just 0.04%.
Metered Bills: Actually Going Down
Here's where it gets interesting. For households of two or more people, metered bills are actually decreasing in 2026. The more people in your household, the bigger the saving.
| Household Size | Avg. Consumption | 2025 Total | 2026 Total | Change |
|---|---|---|---|---|
| 1 person | 85 m³ | £539.72 | £540.45 | +£0.73 |
| 2 people | 110 m³ | £655.46 | £651.89 | -£3.57 |
| 3 people | 135 m³ | £771.21 | £763.32 | -£7.89 |
| 4 people | 150 m³ | £840.66 | £830.18 | -£10.48 |
| 5 people | 165 m³ | £910.11 | £897.05 | -£13.06 |
| 6 people | 180 m³ | £979.56 | £963.91 | -£15.65 |
This is good news for families. While single-person households see a tiny increase of 73p, everyone else is paying less. A family of four saves over £10, and a household of six saves nearly £16.
About the Consumption Data
Average consumption figures are from Southern Water's published data. Your actual usage may vary, but these figures represent typical UK households.
Should You Switch to a Meter? The 2026 Analysis
This is the question everyone wants answered. We've compared metered costs (at average consumption) against unmetered costs for every combination of rateable value and household size.
The Simple Answer
- RV 100: Stay unmetered—a meter costs more regardless of household size
- RV 200: Switch if you have 1-2 people; stay unmetered for 3+ people
- RV 300+: Switch to a meter—all household sizes save money
The break-even point sits around RV 180-220 for 1-2 person households. Above RV 200, almost everyone benefits from switching to a meter.
2026 Detailed Comparison: RV vs Household Size
Green cells mean you'd save money on a meter. Red cells mean you'd lose money.
| RV | Unmetered | 1 person | 2 people | 3 people | 4 people |
|---|---|---|---|---|---|
| £100 | £463.68 | LOSE £77 | LOSE £188 | LOSE £300 | LOSE £367 |
| £200 | £727.10 | SAVE £187 | SAVE £75 | LOSE £36 | LOSE £103 |
| £300 | £1,013.31 | SAVE £473 | SAVE £361 | SAVE £250 | SAVE £183 |
| £400 | £1,299.52 | SAVE £759 | SAVE £648 | SAVE £536 | SAVE £469 |
| £500 | £1,585.73 | SAVE £1,045 | SAVE £934 | SAVE £822 | SAVE £756 |
| £600 | £1,871.94 | SAVE £1,331 | SAVE £1,220 | SAVE £1,109 | SAVE £1,042 |
The Biggest Winners
The people who benefit most from switching to a meter are:
- Single occupants in high-RV properties — An elderly person living alone in a property with RV 600 could save over £1,300 per year
- Couples in properties with RV 300+ — Savings of £350+ per year are common
- Anyone with RV 400+ — Even a family of six saves over £300 annually
Real-World Example
Remember the 97-year-old resident we mentioned in our calculator guide? In 2025, they were paying £1,237 unmetered but would have paid just £586 metered—a saving of £651.
In 2026, the unmetered bill would rise further while the metered cost would actually fall slightly. The case for switching has never been stronger.
Year-on-Year Trends: What's Actually Happening?
Looking at the data, we can identify some clear trends:
1. Unmetered Pricing Is Becoming Less Favourable
While the increases are small in absolute terms, unmetered customers are consistently seeing their bills rise. The minimum charges (for very low RV properties) are increasing, which is why lower RV properties see larger percentage increases.
2. Metered Pricing Is Becoming More Favourable
The volumetric rates and standing charges for metered customers have shifted in a way that benefits larger households. This suggests water companies are trying to encourage meter uptake by making it more attractive.
3. The Break-Even Point Is Shifting
In 2025, the meter switching break-even was around RV 180-200 for couples. In 2026, it's shifted slightly lower—making meters beneficial for even more households.
Social Tariff Updates for 2026
If you're on a low income, the tariff caps have also been updated:
| Tariff | 2025 | 2026 | Change |
|---|---|---|---|
| Social Tariff Supply Cap | £91.12 | £94.00 | +£2.88 |
| Social Tariff Income Threshold | £21,000 | £22,020 | +£1,020 |
| WaterSure Supply Cap | £158.61 | £162.82 | +£4.21 |
| WaterSure Sewage Cap | £421.00 | £405.00 | -£16.00 |
Good news for WaterSure customers: the sewage cap has actually decreased by £16. And the income threshold for Social Tariff eligibility has increased, meaning more households may now qualify.
The Bottom Line
The 2026 tariff changes reinforce what we've been saying: if you have a high rateable value and a small household, you're almost certainly overpaying on an unmetered supply.
The changes this year make meters even more attractive:
- Unmetered bills are rising (by up to 2.18%)
- Metered bills are falling for households of 2+ people
- The savings gap is widening
- WaterSure customers benefit from a lower sewage cap
If you haven't already, use our calculator to check your specific situation. And remember: Portsmouth Water allows you to switch back to unmetered billing within 12 months if you're not saving money. There's very little risk in trying.