In the guide
If you weigh or measure goods to sell to consumers, the law states that your equipment must be both suitable and accurate
The law also covers the manufacture and approval of this equipment, and lays down requirements about specific quantities in which certain goods must be sold.
Generally the law requires the majority of food, drink and other goods sold to the public to have their quantities indicated for the customer. This includes goods that are weighed or measured at the customer's request or packaged ready for sale.Back to top
Nearly all measurable goods must have their quantities stated in metric amounts - for example, kilograms, litres or metres. Note that the pint must be used for draught beer, lager and cider; milk in returnable bottles may also be sold by the pint.
Equivalent 'imperial' quantities - such as pounds, ounces, pints and yards - can be given in addition to the required metric indications, but they must not be more prominent.
Some products have to be sold in particular or 'prescribed' quantities:
- unwrapped loaves of bread: 400 g or 800 g
- beer, lager and cider: 1⁄3 pint, 1⁄2 pint, 2⁄3 pint or multiples of 1⁄2 pint
- wine: 125 ml, 175 ml or multiples of 125 ml or 175 ml
- whisky, gin, rum or vodka: 25 ml or 35 ml or multiples of 25 ml or 35 ml
For detailed information, check the specific In-depth Guides below for the items you sell.Back to top
Consumers must be able to see what the quantity is for goods required to be sold by weight or measure. This must be included on the products' labels. Some fruit and vegetables are not included as they can be counted easily through the packaging. See Quantities above for information on the prominence of the quantity information.Back to top
Non-prepacked goods that are weighed at the request of the customer must have their unit price indicated to the customer by price per kilogram. The price per pound can be given in addition, provided it is not more prominent than the metric price.
Although they are not required to, some traders add the price per 100 g for high-value goods such as cheese and meat to give a more meaningful price indication to consumers.
Some goods traditionally sold in smaller quantities are allowed to be priced in smaller units where this allows the customer a better indication of the value of the goods.
Examples of this are sugar confectionery and chocolate, herbs, spices and coffee - these can be price marked per 100 g.
In larger self-service shops, goods that are sold by weight or measure are required to display an equivalent unit price for goods sold with an indication of quantity - for example, equivalent price per 100 g (or 100 ml). This is to allow consumers to compare the relative values of similar products that are sold in different quantities.Back to top
Weighing and measuring equipment
Equipment that is used to weigh or measure goods for consumers must be suitable for the quantity being determined and accurate within specific tolerances.
Equipment used for consumer sales is required to be 'Government stamped'; this refers to markings that show the equipment has been made to a particular standard and meets accuracy requirements.
Government stamps generally take the form of either:
- a lead plug embedded into the equipment on which is stamped a numbered crown and year
- a series of stickers attached to the equipment
Information plates on some equipment also give other required details.
Measuring equipment that has tested as inaccurate or no longer conforms with other requirements will have a six-pointed star stamped on or attached to it. Look out for this if you're buying second-hand equipment.
Construction requirements, measuring capacity and accuracy tolerances requirements also vary with the value of the goods being sold. Equipment used to buy and sell gold, silver, etc has different requirements to that used to sell potatoes.
Here are some examples of weighing and measuring equipment (consumer sales) that are required to be stamped:
- weighing machines, used for fruit and vegetables, sweets, meat, fish, postal services, etc
- measures of volume:
- beer glasses and automatic measuring meters
- alcoholic spirits measures ('optics') and 'thimble' measures
- wine glasses and carafes
- petrol pumps
- length measures:
- commonly known as 'yardsticks' but which must now be metre measures used for material, fabrics, ribbon, electrical cable, etc
- flexible tapes, used for carpet and other floor coverings
New weighing and measuring equipment intended for determining the quantity of goods sold has to be manufactured to an evaluated and approved type, called a 'type examination certificate' (TEC). This means that the design and construction of the equipment must have been evaluated, approved and certificated by UK or European legislation and have the appropriate required markings and details attached to it.
This equipment is then subject to periodic inspection for accuracy and continued conformity by trading standards officers who are qualified in weights and measures.
These inspections will be scheduled at intervals determined by the use that the equipment is put to and the likelihood that it may wear and become inaccurate. They could be as frequent as every six months or as far apart as five years.
If weighing and measuring equipment is found to be not of the required accuracy when inspected, the inspecting officer may issue instructions to have the equipment adjusted.
For more serious discrepancies, the officer may 'reject' the equipment, thus revoking its qualifying stamp with the six-pointed star (above). This means that the equipment cannot be used again until it has been repaired to the requirements of the TEC and re-stamped.
Where serious fraud is suspected involving the use of weighing and measuring equipment it could be seized, followed by possible legal proceedings.
For more detailed information please see the In-depth Guides below. Once you've finished, make sure you look at the full range of Quick Guides to see whether there are any other areas of law that affect your business.
Make sure you choose your location using the drop-down list at the top of the page. The In-depth Guides provide country-specific information as some laws are different in England, Scotland and Wales, and some are enforced differently
In-depth guidanceThis is a general guide and you may well need to know more; take a look below where we've listed our In-depth Guides on specific topics related to weights and measures
When selling goods and providing services, in most circumstances, the consumer must be informed of the selling price in writing
An overview of 'average quantity' and what is required of packers or importers of packaged products
It is essential that oil and gas are accurately weighed or measured when sold and delivered
The weight of solid fuel must be specified; this also applies to wood if a relevant bye-law exists, or you opt to show weight
Businesses who sell products in containers provided by consumers are subject to a variety of legal requirements
Food and drink
Requirements for the sale of alcohol in pubs, restaurants, etc
The three rules of packing to the average-weight system for small bakers
Requirements for butchers regarding products sold loose and/or prepacked
Requirements for fishmongers regarding products sold loose and/or prepacked
Requirements for greengrocers regarding products sold loose and/or prepacked
Equipment and instruments
Weighing equipment that is used for legal and trading purposes is required to be accurate and appropriate for its purpose