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Shark Cordless Stick Vacuum with Auto Empty System BU3521UK

Shark

Shark Cordless Stick Vacuum with Auto Empty — Prices & Offers

Data last updated: · 6 offers tracked

View full specs

Lowest price

£69.99

at Kelkoo

Prices are a snapshot from our tracked retailer feeds, not a live price check — always confirm the current price and stock before buying.

How much does the Shark BU3521UK cost in the UK?

Based on tracked UK retailer prices captured on 13 September 2026, the Shark Cordless Stick Vacuum with Auto Empty System BU3521UK was listed between £69.99 and £349.99 across six tracked offers. That's a wide spread, and unlike a gradual step-up across retailers, most of it comes down to a single listing sitting well below everything else.

The £69.99 figure comes from Kelkoo, a price-comparison aggregator rather than a retailer selling stock directly, and its availability wasn't confirmed at the time of capture. It's roughly a third of the next-lowest tracked price, which is a bigger gap than normal retailer variation typically produces — it more plausibly reflects a stale, mismatched or unverified listing than a genuine current price on this model. We'd treat it with real caution rather than lead with it as the price.

Looking at the other five tracked offers, prices form a more consistent band from £259.66 to £349.99, with In Stock confirmed at four of those five sources. That £259.66–£349.99 range is the more representative picture of what this model actually costs from a UK retailer right now.

Where to buy the Shark BU3521UK — tracked prices

RetailerPriceStock status
Kelkoo (price comparison)£69.99Unconfirmed
eBay£259.66In stock
idealo (price comparison)£277.77Unconfirmed
Amazon.co.uk (Marketplace seller)£316.20In stock
Freemans£349.99In stock
J B Postle & Sons£349.99In stock

This is a single snapshot from 13 September 2026, and prices move as retailers adjust listings and stock sells through. Two of the six sources here — Kelkoo and idealo — are comparison feeds rather than direct retailers, and neither had confirmed stock at capture, so treat their figures as a starting point for checking rather than a guarantee of what you'll pay at checkout. Before ordering from any listing, especially the lowest one, confirm current price and availability directly with the retailer. For a live view rather than this fixed snapshot, the comparison tool tracks offers as they change.

What affects the price you pay

A handful of factors typically explain why tracked prices for the same machine can differ this much:

  • Listing type. Direct retailers with confirmed stock (eBay, Amazon.co.uk marketplace, Freemans, J B Postle & Sons) tend to reflect what you'd actually pay today. Comparison-aggregator prices, like Kelkoo and idealo here, can lag behind current stock and pricing, since they pull from feeds that aren't always refreshed in step with the retailer's own site.
  • What's included at the quoted price. Confirm the listing covers the full Auto-Empty Dock, Crevice Tool and Pet Multi-Tool set, not a stripped-down bundle without the dock — the auto-empty base is the machine's main selling point and a listing missing it isn't a like-for-like comparison.
  • Seller and warranty terms. Marketplace listings, including the Amazon.co.uk Marketplace Seller offer tracked here, can differ from the manufacturer's own warranty and return terms even when the headline price looks similar to a direct retailer.
  • Timing. A snapshot like this catches prices at one moment; stock levels and short promotions shift the figure in either direction between checks.

What you're paying for: key specification

SpecFigure
Power input240W
RuntimeUp to 40 minutes
Dust cup capacity0.42L (bagless, empties automatically into the sealed Auto-Empty base)
Weight2.66kg
Noise level82dB
BatteryLi-ion 2.5Ah
Accessories includedAuto-Empty Dock, Crevice Tool, Pet Multi-Tool

These figures are Shark's published specification for this exact model and hold regardless of which retailer you buy from — the price differences tracked above reflect the listing source, stock confirmation and timing, not a difference in the machine itself. Two features stand out at this price point: the Auto-Empty base, which holds dirt and debris for up to 30 days before you need to deal with it, and the Anti-Allergen Complete Seal, which Shark states captures up to 99.9% of dust, allergens and irritants inside the base rather than the main unit. The self-cleaning PowerFins brush-roll auto-adjusts between carpet and hard floor and includes anti-hair wrap technology, while an LED display shows remaining battery life and cleaning mode, and LED headlights on the floorhead light up hidden debris as you clean.

If you're comparing this model against other cordless stick vacuums with auto-empty docks, it's worth weighing these specifics — dust cup capacity, dock hold time and battery runtime especially — against price rather than looking at price alone. For a closer look at how these features perform in practice, the full Shark BU3521UK review covers the machine in more depth than this pricing-focused page does. You can also browse other Shark vacuum cleaners if you'd rather stay within the brand but consider a different tier or form factor.

Is the £69.99 Kelkoo price for the Shark BU3521UK genuine?

Treat it with caution. Kelkoo is a price-comparison aggregator, not a direct retailer, its stock status was unconfirmed at capture, and the figure sits roughly a third of the next-lowest tracked price. That gap is larger than normal retailer variation, so it more likely reflects a stale or mismatched listing than a current, buyable price. Confirm price and stock directly with the retailer before relying on it.

What's a realistic UK price range for the Shark BU3521UK?

Excluding the unconfirmed Kelkoo listing, tracked offers ran from £259.66 to £349.99 as of 13 September 2026, with in-stock confirmation at eBay, Amazon.co.uk (Marketplace Seller), Freemans and J B Postle & Sons. eBay's £259.66 was the lowest confirmed in-stock price, while Freemans and J B Postle & Sons both listed the machine at £349.99, the top of that range. A separate aggregator listing on idealo at £277.77 also sat within the band but, like Kelkoo, had unconfirmed stock at capture. For a live view of current prices rather than this fixed snapshot, check the comparison tool before buying.

Does the Shark BU3521UK price include the Auto-Empty Dock?

Shark's standard accessory set for this model includes the Auto-Empty Dock, a Crevice Tool and a Pet Multi-Tool. Always check a listing's description confirms the dock is included, since the auto-empty base is the model's main selling point and a bundle without it isn't the same product. The dock itself holds dirt and debris for up to 30 days before it needs emptying, and works alongside the Anti-Allergen Complete Seal, which Shark states captures up to 99.9% of dust, allergens and irritants inside the base rather than the main unit — features worth confirming before you buy.

How long does the Shark BU3521UK run on a charge?

Up to 40 minutes, from a 2.5Ah lithium-ion battery, which is Shark's published runtime figure for this exact model regardless of which retailer you buy from. The BU3521UK pairs that battery with a 240W motor and a self-cleaning PowerFins brush-roll that auto-adjusts between carpet and hard floor, plus an LED display that shows remaining battery life and cleaning mode as you use it. Actual runtime in practice will depend on the power setting and floor type, since higher suction and denser carpet both draw more from the battery than light hard-floor cleaning.

How long can the Auto-Empty base go before it needs emptying?

Shark states the Auto-Empty base holds dirt and debris for up to 30 days before it needs emptying, with the Anti-Allergen Complete Seal keeping dust and allergens sealed inside the base rather than the main unit, capturing up to 99.9% of dust, allergens and irritants according to Shark. That capacity is based on a 0.42-litre bagless dust cup that empties automatically into the sealed base each time you dock the machine, rather than requiring you to empty a handheld bin after every session. Actual time between empties will vary with how often and how much you vacuum.