2026 Data
UK's Best Tap Water: Top Rated Postcodes
The UK postcodes with the highest water quality scores. Ranked by TapWater.uk safety score.
According to TapWater.uk's analysis of 1,942 UK postcodes, the best-scoring postcode achieved 9.8/10.
9.8
Top score
9.1
UK average
Top 50 postcodes
Ranked by highest safety score. Click any postcode for a full water quality report.
Scores are based on 1,942 postcode districts with Environment Agency data. Score methodology: contaminant levels measured against UK legal limits and WHO guidelines.
What this means
TapWater.uk's safety score rates water quality from 0 to 10 based on measured contaminant levels against UK legal limits and WHO guidelines. A score of 10 means all tested parameters are well within safe thresholds. Higher scores indicate fewer contaminants and lower concentrations relative to safety limits.
How to protect yourself
Even in areas with excellent water quality, a simple carbon jug filter can improve taste by reducing chlorine. This is purely optional for preference rather than safety.
Check your postcode
See the full water quality report for your area, including all tested contaminants and personalised filter recommendations.
Frequently asked questions
Which UK postcode has the best tap water?
The postcodes with the highest water quality scores are typically in areas with clean upland water sources, low population density, and modern infrastructure. Scotland and Wales tend to score well due to soft, low-contaminant water from mountain reservoirs.
What makes tap water score highly?
High-scoring water has low levels of all tested contaminants relative to both UK legal limits and stricter WHO guidelines. Key factors include low lead, nitrate, and pesticide levels, no PFAS detected, and minimal treatment byproducts like trihalomethanes.
Does a high score mean I don't need a water filter?
A high safety score means your water is well within safe limits for all tested parameters. Whether you need a filter depends on personal preference — some people use filters to improve taste, reduce chlorine, or provide extra peace of mind. Even the best-scoring water may benefit from a simple carbon filter for taste.
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Highest Nitrate Levels
Nitrate levels by UK postcode. Data from Environment Agency and water company testing.
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PFAS Detections
Which UK postcodes have PFAS forever chemicals in nearby water sources? Environment Agency monitoring data.
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The UK postcodes with the hardest water. Ranked by calcium carbonate levels.
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Worst Water Quality
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