Best Water Filter UK (2026): Jugs, Under-Sink and RO Compared

Do you actually need a water filter in the UK?

For most homes, UK tap water already meets strict legal standards. Which? points to Drinking Water Inspectorate (DWI) figures showing 99.9% of samples met standards, and says filtering out trace contaminants is unlikely to make a meaningful difference for most people (Which?). So the honest answer is: you do not need a filter, but there are good reasons to want one.

The three most common UK reasons are:

• Lead pipes. Homes built before 1970 may still have lead pipework. The DWI's first advice is to run the tap, ask your water company to test, and replace the pipes (DWI). A filter certified for lead is a sensible stopgap while you sort that out.
• PFAS ("forever chemicals"). There is no legal PFAS limit in England and Wales yet. The DWI uses a precautionary guideline of 0.1 micrograms per litre for the sum of 48 PFAS, and water companies must act if they exceed it (DWI). Some people want to lower their exposure further.
• Taste and hard water. Chlorine or chloramine (a chlorine and ammonia disinfectant some suppliers use) can taste strong, and hard water leaves scale in kettles. The DWI says hard water is not a health standard issue in the UK (DWI).

Our picks at a glance

How we chose

We checked each filter against public certification listings, not just the box. NSF/ANSI 42 covers taste and smell, NSF/ANSI 53 covers named health contaminants such as lead and PFOA/PFOS, NSF/ANSI 58 covers reverse osmosis (RO), and NSF/ANSI 401 covers emerging compounds such as some medicines and microplastics (NSF). Certification can come from NSF itself or other accredited bodies such as IAPMO R&T and WQA, and each claim is listed contaminant by contaminant. We favoured products with listings for the exact model, verified UK prices on brand or major UK retailer pages, and graded anything with only brand wording as moderate or limited.

Which type of water filter should you buy?

Jug filters

Cheapest and no installation. Carbon plus ion-exchange jugs reduce chlorine taste and temporary hardness. Only some are certified for health contaminants. In an independent 2024 study of 75 PFAS, results ranged from about 99 to 100% removal (ZeroWater) down to 20 to 48% (Brita Elite) (Frontiers in Environmental Chemistry). Jugs need regular cartridge changes and should be kept in the fridge (ANSES).

Tap and countertop filters

These connect to your existing tap with a diverter. Ceramic plus carbon systems such as Doulton keep minerals and waste no water. Good for renters.

Under-sink filters

A cartridge under the sink feeds either your existing tap or a separate drinking tap. Two-stage carbon systems can perform very well: the Duke and NC State study found under-sink two-stage and RO filters removed nearly all PFAS tested (Herkert et al. 2020).

Reverse osmosis (RO)

RO pushes water through a very fine membrane and is the broadest option, covering lead, PFAS, nitrate, fluoride and dissolved solids under NSF/ANSI 58. Trade-offs: waste water (1 litre to drain for every 2 to 3 litres filtered on modern units), power, a drain connection, and water with very few minerals. See our reverse osmosis guide.

Gravity filters

Countertop tanks with ceramic or carbon candles. Popular off-grid, but certification often covers cysts and particles rather than chemicals. Read the data sheet.

Our picks in detail

ZeroWater 5-Stage Water Filter Jug: best jug for certified lead and PFOA/PFOS

IAPMO R&T certifies the ZeroWater cartridge to NSF/ANSI 53 for lead, mercury, PFOA, PFOS and hexavalent chromium (TapWaterData). It was also the top jug for total PFAS in the 2024 study (Frontiers). Caveat: it strips minerals too, so in hard water the cartridge can be spent within weeks, which raises running costs.

BRITA Marella Jug with MAXTRA PRO: budget pick

At £29.99 it is the cheapest sensible upgrade for taste and kettle scale. Belgian consumer group Test-Achats found a Marella with MAXTRA PRO removed up to 96% of some PFAS and all four PFAS that EFSA regulates (Test-Achats). Caveat: this is a single consumer test, not a certification, and BRITA publishes no lead percentages.

Waterdrop G3P600 Reverse Osmosis System: premium pick

Certified by IAPMO R&T to NSF/ANSI 42, 53 (including PFOA/PFOS) and 58 (including lead and TDS) (TapWaterData). It is tankless, so it fits smaller cupboards, and wastes 1 litre for every 2 filtered. Caveat: needs a plumber, a socket, a drain connection and a separate tap.

AquaTru Classic Countertop Reverse Osmosis: best RO without plumbing

IAPMO lists the Classic under NSF/ANSI 42, 53, 58 and 401, covering lead, PFOA/PFOS and microplastics (TapWaterData). You fill it from the tap. Caveat: £475, bulky, and sold out on AquaTru UK when we checked.

Doulton Countertop Water Filter Systems: best tap-connected filter

Uses Doulton's Biotect Ultra ceramic and carbon cartridge, which Doulton says is NSF-certified to 42, 53 and 401. Its predecessor cartridge showed over 99% lead reduction in NSF testing on file with California's water board (data sheet). Caveat: no PFAS claim, and we could not open a live NSF listing for Biotect Ultra itself.

BRITA Glass Jug with MAXTRA PRO cartridge: best glass jug

Same cartridge as the Marella in a glass body, so less plastic touches stored water. Caveat: the lid and cartridge are plastic, and there is no certified lead or PFAS claim.

Waterdrop 10UA Under Sink Water Filter: cheap under-sink taste fix

Fits inline to your existing tap and lasts about a year. Caveat: certified only to NSF/ANSI 42 for chlorine taste, so do not rely on it for lead or PFAS.

British Berkefeld Stainless Steel Gravity System + Ultra Sterasyl: off-grid pick

Stainless steel with ceramic candles, no power or plumbing. Caveat: Doulton's own NSF data covers cysts, particles and cloudiness only (instructions PDF). PFAS and lead claims on the product page are not certified.

ZeroWater 1.7L Jug with TDS Meter: best small jug

Same certified cartridge family as the larger ZeroWater, sized for a fridge door. Caveat: frequent refills.

What the evidence says about home filters

• Type matters more than brand. Under-sink RO and two-stage filters removed nearly all PFAS in real homes; other carbon filters were inconsistent; some whole-house systems increased PFAS (Herkert et al. 2020).
• Certification is claim by claim. A product "NSF certified" to 42 only is a taste filter. Look for 53 or 58 and the specific contaminant (US EPA).
• Maintenance is not optional. Old cartridges can release what they trapped and grow bacteria (Which?, ANSES).
• Boiling does not remove PFAS (NSF).
• RO water is low in minerals. The WHO has reviewed long-term drinking of demineralised water; many RO units add a remineralising stage (WHO).

What to avoid

• Vague "removes 99% of contaminants" claims with no named standard or certifier.
• Whole-house carbon units bought to reduce PFAS at the drinking tap.
• Water softener water for drinking or baby feeds; the DWI recommends an unsoftened drinking tap (DWI).
• Ignoring cartridge schedules in hard water areas.

Bottom line

If you want a cheap, certified upgrade, the ZeroWater jug is the strongest jug we found for lead and PFOA/PFOS. If you own your home and want the broadest certified reduction, an NSF/ANSI 58 RO system such as the Waterdrop G3P600 is the most thorough choice. If you mainly want better taste, a BRITA jug is fine. And if your home predates 1970, ask your water company about lead pipes before you spend anything. For background, read what PFAS are and our PFAS filter guide.