Water filters in the UK range from £10.99 to £76 for the unit itself, but the cartridge costs you replace every four to eight weeks are what determine your real annual spend. Whether you live in a hard-water area like London or the South East, or simply want better-tasting tea, this guide breaks down every cost so you can budget accurately before you buy.
What to look for
01Upfront jug price: what £10.99 to £76 actually buys you
The cheapest tracked unit in this category is the AQUAPHOR Water Filter Jug Compact with 1 X Maxfor+ Filter at £10. 99. At that price you get a 2.4L jug and one starter cartridge. Spend around the category average of £26.06 and you typically get a larger jug (3.5L is common), a digital filter-change indicator, and sometimes a multi-pack of cartridges bundled in. Above £40 you start to see under-sink or countertop systems with longer filter lifespans and higher flow rates. The BRITA Marella XL (3.5L) is currently the biggest discounted pick in the category, sitting 17.4% off its 90-day high and saving you £4.01. Prices across the 23 products tracked average £26.06, so anything below that is genuinely budget territory, and anything above £50 should come with meaningfully better filtration specs or a longer cartridge life to justify the outlay.
02Cartridge running costs: the number that matters most
Most jug cartridges are rated for 150L to 200L of filtered water, which works out to roughly four to eight weeks of use for a typical two-person household. A single Brita Maxtra Pro cartridge bought individually costs more per unit than a 12-pack, which is currently £54.99 (down from a 90-day high of £43.88 on smaller packs). Third-party compatible cartridges, such as the FilterLogic Universal 6-pack at £12.49, can cut your annual cartridge bill significantly compared with branded refills. If you live in a hard-water area, the South East in particular, you may need to replace cartridges at the shorter end of the rated interval because limescale loads up the ion-exchange resin faster. Factor in roughly £30 to £60 per year in cartridges for a jug filter, or £60 to £120 for an under-sink system with longer-life filters, when comparing total cost of ownership.
03Jug capacity and fridge fit: 2.5L vs 3.5L for UK kitchens
Most UK fridge doors have a shelf height of around 280mm to 320mm, which comfortably fits a standard 2. 5L jug such as the Aqua Optima Liscia or the Waterdrop PT-05B Elfin. Step up to a 3.5L jug like the BRITA Marella XL and you may find it only fits on a main fridge shelf rather than the door, taking up more space. For a one- or two-person household, 2.5L is usually sufficient and refills once or twice a day. Families of four or more will find a 3.5L jug reduces the number of refill trips noticeably. Check the jug's footprint in centimetres before buying: the Marella XL is designed with a slim profile specifically to fit standard 60cm fridge shelves, which is a practical advantage in smaller UK kitchens.
04Price volatility: when to buy and how much to save
Across the 23 water filter products tracked, the average discount off the 90-day high price is 7. 5%. That is not dramatic, but it is consistent, meaning patience does pay. The BRITA Marella XL Blue is the standout example right now, at 17.4% off and saving £4.01 versus its recent peak. Cartridge multi-packs tend to see the sharpest percentage drops because retailers use them as promotional lines. The BRITA MAXTRA PRO Pure Performance 12-pack, for instance, has ranged from £34.99 to £54.99 over 90 days, a swing of £20.00. If you are not in a rush, setting a price alert on Amazon UK for your preferred cartridge pack is a straightforward way to catch those dips. Avoid buying a starter jug at full price if the same model has been lower within the past three months.
Our top picks
Best for budget-conscious first-time buyersAqua Optima Liscia Water Filter Jug
At £11.24 (with a 90-day low of £9.00), the Aqua Optima Liscia bundles a 2.5L fridge-friendly jug with three Evolve+ cartridges, giving you roughly three months of filtered water straight out of the box. It is dishwasher-safe, which saves time, and the easy-fill lid is genuinely useful if you refill it one-handed at the tap. Rated 4.6 stars across nearly 10,000 reviews, it is a low-risk entry point for anyone new to jug filters.
Best large-capacity jug at a discounted priceBRITA Marella XL Water Filter Jug
The BRITA Marella XL Blue is currently 17.4% off its 90-day high, saving £4.01 and bringing it to £18.99. You get a 3.5L jug with a digital LTI filter-change indicator and a Flip-Lid for one-handed pouring, plus one MAXTRA PRO Pure Performance cartridge included. The 3.5L capacity suits families or anyone who drinks a lot of hot drinks, and the slim profile is designed to fit standard 60cm UK fridge shelves.
Best for keeping cartridge running costs lowFilterLogic Universal 6 Pack Filter Cartridges
The FilterLogic Universal 6-pack at £12.49 (its 90-day low, and currently at its lowest tracked price) is compatible with Brita Maxtra+, Maxtra Pro, PerfectFit, and Marella jugs, as well as Bosch Tassimo machines. Six cartridges for £12.49 works out to around £2.08 each, substantially less than branded equivalents. With 15,304 reviews and a 4.4-star average, it is a well-proven way to cut your annual filter spend without switching jugs.
Best for households wanting PFAS and pesticide reductionBRITA MAXTRA PRO Pure Performance Water
The BRITA MAXTRA PRO Pure Performance 12-pack is £54.99 right now, down from a 90-day high of £43.88 on smaller pack sizes, making the bulk buy the smarter option per cartridge. Each filter is certified to reduce chlorine, PFAS, pesticides, and limescale, which matters if you are in a hard-water area or concerned about trace contaminants. At 4.8 stars from over 10,000 reviews, it is the highest-rated product in this category.
Frequently asked
How much does a water filter jug cost to run per year in the UK?
Budget roughly £30 to £60 per year on cartridges for a standard jug filter, assuming you replace the filter every four to eight weeks as recommended. If you buy branded cartridges individually, costs sit at the higher end. Switching to compatible third-party packs, such as the FilterLogic Universal 6-pack at £12.49 for six, can bring annual running costs closer to £25 to £35. Hard-water households in areas like London or the South East may need to replace cartridges more frequently, pushing costs toward the top of that range.
Are third-party water filter cartridges as good as Brita originals?
Compatible cartridges from brands such as FilterLogic use the same ion-exchange resin and activated carbon construction as branded versions and are designed to fit the same jugs. They will not carry Brita's own certification marks, but many are NSF-referenced or independently tested. The FilterLogic Universal 6-pack has over 15,000 Amazon UK reviews at 4.4 stars, which suggests real-world satisfaction is high. If you have a specific filtration concern, such as PFAS or pesticide reduction, check the cartridge's published test data rather than relying on brand name alone.
What is the cheapest water filter jug available in the UK?
The cheapest tracked option across 23 products is the AQUAPHOR Water Filter Jug Compact with 1 X Maxfor+ Filter at £10.99. It has a 2.4L capacity and includes one starter cartridge. The Aqua Optima Liscia with three cartridges is also available from £11.24, making it slightly pricier upfront but better value when you factor in the bundled filters. Both sit well below the category average of £26.06.
Do water filter jugs work in hard-water areas like London?
Yes, and they are particularly useful in hard-water areas. The ion-exchange resin in most jug cartridges reduces limescale-causing calcium and magnesium ions, which improves the taste of tea and coffee and reduces kettle furring. In very hard-water areas (above 300mg/L, common across the South East and East Anglia), you will likely need to replace cartridges at the four-week end of the recommended interval rather than eight weeks, because the resin saturates faster. Some cartridges, such as the BRITA MAXTRA PRO Limescale Expert, are specifically formulated for high-hardness water.
Is it worth buying a water filter cartridge multi-pack?
Almost always, yes. Multi-packs consistently offer a lower cost per cartridge than buying individually, and prices fluctuate enough that timing matters. The BRITA MAXTRA PRO Pure Performance 12-pack has ranged from £34.99 to £54.99 over 90 days, a difference of £20.00. Buying at the lower end of that range cuts your per-cartridge cost significantly. Set a price alert on Amazon UK and buy a larger pack when the price dips, rather than purchasing single cartridges reactively when your current one runs out.