WaterMark Certification Explained

WaterMark is the Australian certification scheme for plumbing products that connect to mains water supply. It is not optional - Australian state plumbing regulations require WaterMark certification on every product fitted to mains-pressure water supply. That includes filters, taps, fittings, valves, and any product where a failure could contaminate the supply or damage downstream plumbing.

The scheme exists because failure modes on mains-pressure plumbing are expensive. A tap that splits, a filter housing that cracks, a backflow prevention valve that does not - all of those cause property damage, water contamination, and council issues. WaterMark certification means the product has been tested against the relevant Australian Standards (the AS/NZS 3500 series for plumbing, AS/NZS 4020 for products in contact with drinking water, plus product-specific standards) and is approved for mains-pressure installation in Australia.

Who issues the certification

Three Joint Accreditation System of Australia and New Zealand (JAS-ANZ) accredited certifiers issue WaterMark licences:

• IAPMO Oceana
• SAI Global
• Global-Mark

A certified product carries a WaterMark licence number (typically formatted WMK-XXXXX) issued by one of those bodies. The licence covers a specific product specification - substituting parts or modifying the product invalidates the certification.

Where it applies

WaterMark applies to anything plumbed into mains water supply in Australia. The most common categories on this site:

• Whole-house water filters - they sit on the mains, certification required.
• Under-sink filters connected to mains-pressure cold-water lines - certification required for the housing and any included fittings.
• Kitchen and bathroom taps - every mains-pressure tap, mixer, and outlet.
• Toilet cisterns and pans - mains-fed, certification required.
• Backflow prevention valves and pressure-reducing valves - certification required.

WaterMark does not apply to:

• Bench-top filters that connect to an existing tap with a removable diverter - they are not plumbed into the mains.
• Caravan, RV, and off-grid systems that run on tank or pump pressure rather than mains.
• Rainwater-only systems including UV sterilisers fed from a tank.
• Cartridges themselves - the cartridge inside a certified housing is not separately certified.

Non-certified products on this site are clearly labelled "Not WaterMark certified - for off-mains use only". They are perfectly legal for the off-mains applications above, and they are often cheaper than the certified equivalents because the certification process itself adds cost.

Verifying a licence

Where a WaterMark licence number is held in our current product records, we list it on the product page under Specifications or Compliance. You can use that number to verify the certification in the official WaterMark Product Database.

If a product is intended for mains installation and the licence details are not shown on the page, verify the exact product in the official WaterMark Product Database or contact us before installation.