Use of Measures in Trade

No person shall use for trade any unit of measurement not set out in the schedule to the Weights and Measures Act (as amended from time to time). The linear, square, cubic, capacity measure so included shall be used. The use of a unit or capacity measure not specified for the purpose of trade is an offence.Imperial indications are permitted in addition to the requisite metric indication provided the metric indication is the more prominent.

Weighing and measuring equipment used for trade of certain designated types, must be approved and passed by an inspector or approved verifier. It should bear a stamp indicating that it has been so passed. Use while it is not so passed and stamped is an offence. The equipment is liable to forfeiture.

It is an offence to possess such equipment for the purpose of a trade. It is an offence to use in a trade weighing or measuring equipment which is false or unjust. It is an offence to be in possession of any such equipment for use in a trade. It is a defence that the person who used the equipment did so in the course of employment by another person and he did not know nor might reasonably have been expected to know that the equipment was false or unjust.

It is an offence fraudulently to use for trade any weighing or measuring equipment. It is an offence to sell or purport to sell goods by weight or other measure or number or to deliver a lesser quantity than that purported to be sold or correspond to the price charged.  A statement in relation to the weight of the goods may be taken as a reference to the net weight unless otherwise provided.

Packaged Goods

In the case of pre-packaged goods, if the quantity is less than stated, a person who has the goods in his possession for the purpose of sale is guilty of an offence. If the shortfall is not attributable to anything occurring after they were sold by retail sale and delivered to the buyer, the buyer is guilty of an offence.

Where goods are not prepacked but are made up for sale or delivery it is an offence if the quantity of the goods is less than the quantity stated on the container or document and the shortfall is not referable to something which happened after delivery to the buyer.

It is a defence for a person who would be guilty of an offence to prove on the balance of probabilities

  • that he bought the goods from another on the basis of the quantity purported to be sold on the container/label
  • the other provided a warranty that the goods were of the quantity also confirmed
  • he believed the statements in the warranty and had no grounds to believe them to be false
  • in the case of a person outside the UK, steps are taken to confirm the accuracy
  • he took reasonable steps to ensure the goods remained unchanged

The defendant must give a copy of the warranty and notice to the prosecutor at least three days before the hearing. It is a defence for the accused to prove he took all reasonable precautions and due diligence was exercised.

It is a defence to prove that

  • the deficiency arose after the container was marked, the document was completed, or the goods made up for sale
  • the deficiency was wholly attributable to factors for which reasonable allowances were made in stating the quantity of goods.

Where the quantity is in excess it is a defence that the excess is attributable to taking reasonable measures in order to avoid a deficiency

In relation to packaged goods, packers and importers must ensure that the contents are not less on average than the quantity indicated. There may be a tolerable error. The proportion of packages greater than the tolerable negative error must be sufficiently small so that the batches of packages satisfy the requirements in the legislation schedule. No package may have a negative error greater than twice the tolerable negative error. The tolerable negative error is defined


Inspectors have power to

  • inspect and test weighing or measuring equipment which they have reasonable cause to believe are to be used for a trade
  • inspect any instrument which he has reasonable cause to believe are subject to the legislation or
  • enter premises (except a private dwelling) without a warrant where they have reasonable cause to believe the goods and equipment are;
  • seize any article which he has reasonable cause to believe is liable to be forfeited
  • seize documents are goods as may be required for evidence

Weights and measures legislation is enforced by the local weights and measures authority and by the police. Prior notice of the offence alleged is required. Notice is be served within 30 days of the prosecutor considering there is sufficient evidence or within 12 months of the date specified in the notice. In the usual way, officers of a corporate may be guilty of an offence if it was committed by a company with the consent connivance or due to their negligence.


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