Before you buy goods by weight or measure

Always check that the scale or petrol pump is on zero before you are served.

Your rights when buying goods by weight or measure

Is the weight of the package included?

Goods bought by weight or measure must be sold to you by net weight or measure. This means that the weight of any packaging must be excluded from the weight or measure statement.

When goods are weighed in front of you

Goods weighed, measured or counted at the time of sale must be done so in front of you and you must be able to see the whole operation.

Most modern weighing instruments have a tare button. This should be used to zero the weight of the packaging or container before the goods are weighed.

Where goods are pre-packed on the premises, you can request that they be re-weighed, measured or counted in front of you.

Units of measurement

All goods must be sold in metric units, e.g. grams, kilograms, millilitres, litres, metres.

Buying pre-packed goods

Generally, packaged goods which are marked with their quantity must contain the amount stated on the package.

For pre-packed goods of the same kind and stated quantity e.g. 500g packs of butter, this means they must meet the 'average quantity system' rules. These rules set out strict specifications that packers must abide by to control the quantity of pre-packaged goods.

Although it is possible to have a few pre-packed goods containing slightly less than the stated amount, on average across a production run the stated quantity must be correct.

Random checks on packers, importers and retailers are carried out by Trading Standards Officers. These are based on statistically random samples. This gives you greater assurance that you will receive packaged goods that comply with the regulations.

For other pre-packed goods of variable quantity, such as joints of meat, or for non pre-packed goods they must contain at least the stated quantity. The statement could be on a label, invoice, a scale display or whatever the trader tells a customer it is.

Roadside stalls

The same rules apply if you buy from a road side stall. If the goods are weighed in front of you it is worth checking that the scales the trader is using are suitable.

Equipment used to weigh or measure goods

You can look for a 'certificate of accuracy' sticker which shows the scales are checked annually. You should also find, often on the side or back of the scales, a small round lead plug or an adhesive destructible label with a crown or the letters "AP" and a number on it. Sometimes it may be lead seal and wire. This shows the scales are approved for Trade and were tested before they were first put into use.

See What weighing and measuring equipment can my business use?

Buying firewood by volume

Firewood may be sold to you either by volume e.g. 3 cubic metres, or by description e.g. a truckload, trailer load or sackful. It is accepted that firewood is sold as a 'thrown measure', rather than a stacked one.

If you do buy by volume, you should check whether the truck has been 'approved' by Trading Standards. If it is it will have a stamped lead plug with a crown on it or the Certificate of Approval is carried in the vehicle at all times and should have a sign stating its size, eg “3 cubic metre” or “3m3”. Trading Standards can advise you which traders in your area have a certificate of approval for their truck.

When you buy by volume the seller should also provide you with a written invoice that shows the quantity delivered.

Buying coal by weight

Coal (or coke or carbonettes) must be weighed before the sale unless you are filling your own bags or trailer.

Coal can be sold in sacks or bags or loose. If sold in a closed bag, the weight must be shown on the bag itself or on an invoice or delivery note.

If the coal is sold in open bags the seller must provide a written notice showing the net weight of each bag and the number of bags delivered, or the total weight of the bags delivered.

If sold loose, the driver of the vehicle that delivers the coal must give you a written notice.

Garden and landscape supplies by weight or measure

Garden and landscape supplies may be sold to you by weight or measure, by number or by description e.g. a scoop or truckload.

Got a problem with goods sold by weight or measure?

If the quantity is not marked on a package then ask for a written statement of the goods.

What if I got less than I paid for?

If you think you have been sold a short amount you can:

ask the seller to re-weigh or measure the goods in front of you

tell the seller you believe they have sold you short weight or measure

check to see whether the scale or petrol pump has a current certificate of accuracy. You can rely on scales and pumps that have a current certificate.

Complain to Trading Standards

If the seller won't help, keep your receipt and contact Trading Standards. Trading Standards Officers investigate complaints from the public who think they may have been sold short weight or measures goods.

Contact a Trading Standards Officer.

Find out more about Trading Standards.

Penalties for breaking the law

The Ministry can seize short weight or measures goods, or inaccurate weighing or measuring equipment. Infringement Offence Notices for $500 can be issued for each offence.

The courts may impose fines of up to $10,000 for serious breaches, plus $250 a day for each day the breach continues.