The Shark BU3521 takes the Shark Handheld Vacuum Pre-Motor Filter (XPRFIW1000) as its pre-filter; replace it every 12 months; Australian sellers list it from A$14.90 as of 5 October 2026. Fitment confirmed against the manufacturer's compatibility list.

Your vacuum cleaner
Shark BU3521
Stick vacuum
Confirmed against Shark's listConfirmed against Shark Australia's compatibility list
Not yours? ChangeSave it · remind me every 12 months
Takes the XPRFIW1000 pre-filter
Handheld Vacuum Pre-Motor Filter (XPRFIW1000) · replace every 12 months · check the code printed on your old filter before ordering.

Your vacuum cleaner
Stick vacuum
Confirmed against Shark's listConfirmed against Shark Australia's compatibility list

Takes the XPRFIW1000
Pre-filter · every 12 months · check the code on your old filter.
Other Shark vacuum cleaners and their filters and dust bags
The XPRFIW1000 fits the BU3521 only. These Shark models take a different pre-filter:
GenuineGenuine Shark
$29.99
Shark Au · 22 OctLowest genuine · Shark Au · checked 22 Oct
CompatibleCompatible option
$14.90
Bunnings · 5 OctBunnings · checked 5 Oct
Check sellerCheck seller details
Genuine: made by Shark. Compatible: another brand. Check certification on the seller's page.Genuine is made by Shark. Compatible is made by another brand. Check the seller's certification details before choosing.
Lowest compatibleLowest compatible price · $14.90
Bunnings. Compare with genuine below. Some links earn us a commission. Some seller links earn us a commission, at no extra cost to you.
Compare 2 sellers
AUD, before delivery. Each price shows when it was checked.
Compatible options
1 seller
Opens Bunnings in a new tab. Their page is the source of truth for price, delivery and returns.
How long it lasts
Usually every 12 months.
After replacing: Shark: rinse filters in water only (no soap), squeeze out and air-dry for at least 24 hours before refitting; a damp filter can damage the motor. No reset.
Flow slows and taste drops off as the filter fills up. Changing on time is the whole point.
Not due yet?
Get a nudge when your filter is due — it's every 12 months. One email two weeks before, no newsletter. Manage or stop it anytime.
How to change the pre-filter in your Shark BU3521
Watch the guide or follow the steps.
- 1Switch the vacuum off and take it off the charger or unplug it.
- 2Press the release and take the dust cup off the main body; empty it.
- 3Lift the foam and felt filters out of the housing on top of the dust cup and fit the new felt first, then the foam.
- 4Refit the dust cup until it clicks. Rinse the foam and felt monthly and let them dry 24 hours.
Every number this part goes by
- Retail name:
- XPRFIW1000
Sellers list any of these; they are the same part.
About your Shark BU3521

Shark vacuum cleaner, stick vacuum — Clean & Empty. Its pre-filter is the Handheld Vacuum Pre-Motor Filter (XPRFIW1000), part XPRFIW1000, changed every 12 months.
Where the model number is: The rating label is on the underside or the back of the main body; the bag or filter type is usually printed on the old part.
Fits these 1 Shark model
Shark1 model
Common questions
- Which pre-filter fits the Shark BU3521?
- The Shark BU3521 takes the Shark Handheld Vacuum Pre-Motor Filter (XPRFIW1000) (part XPRFIW1000). Compatible filters made to the same specification also fit.
- How often should I replace the pre-filter in my Shark BU3521?
- Every 12 months. Flow slows and performance drops off as the filter fills up, so it's worth doing on time.
- Where can I buy the XPRFIW1000 in Australia?
- We track 2 Australian sellers for the XPRFIW1000; the lowest listed price when we last checked was A$14.90 at Bunnings. Prices are re-checked daily and dated on this page.
- How do I fit the XPRFIW1000 in a Shark BU3521?
- No tools, a few minutes: 4 steps, listed on this page with the replacement video where the maker has one.
- What happens if I don't change it?
- Suction drops and the vacuum may cut out on a blocked filter, and a full bag loses suction well before it looks full.
- How do I reset the reminder?
- Shark: rinse filters in water only (no soap), squeeze out and air-dry for at least 24 hours before refitting; a damp filter can damage the motor. No reset.
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