Identification of livestock

It is a legal requirement that livestock, including livestock kept as pets, are properly identified. The rules relating to identification vary depending on the type of animal in question.

Currently there is no requirement to identify llamas, alpacas, guanacos and vicunas, although this may well change in the future.


All cattle born on or after 1 January 1998 must be “double tagged” within 20 days of the animal being born, with the exception of dairy cattle which must be fitted with at least 1 tag within 36 hours of birth.

All cattle must, however, be double tagged before they leave the holding on which they are born.

The process of double tagging involves the fitting of an ear tag bearing the animal’s unique number to each of the animal’s ears.

There are 2 types of ear tag. These are known as “primary” and “secondary” tags. A “primary” ear tag is a yellow, plastic two-piece ear tag. Primary ear tags fitted since 1 January 2000 must contain the crown logo, country code, “herdmark”, individual animal number and check digit.

A secondary ear tag can contain include additional information which may be help the farmer manage his herd, for example, it could the animal’s name. Button and metal tags can be used as secondary tags since there is no minimum size requirement for secondary tags.

Cattle imported from outside of the EU must be retagged within 20 days of the animal passing the veterinary checks which are required when importing cattle from outside of the EU.

Cattle do not currently have to be electronically tagged in the UK.

Sheep and goats

All sheep and goats born or first identified on or after 1 January 2010 must be identified within 6 months of birth (if they are housed overnight) or within 9 months of birth (if they are not housed overnight) or before they leave the holding on which they were born, if that is sooner.

Sheep and goats intended for slaughter within 12 months of birth need only carry one form of identification. In such circumstance identification can be by tagging or electronic and a single slaughter batch tag (bearing simply the flock number) can be used. Otherwise they must carry 2 forms of identification and in the case of sheep one of these forms of identification must be electronic.

Where identification by electronic means is required or permitted such identification can be by means of a “bolus” (an electronic identifier which the animal swallows).

Where identification by non-electronic means is permitted identification can be by means of ear tags, tattoos and “pastern bands” (a band which is placed around the animal’s lower leg).

Both forms of identification must bear the same individual number which consists of the country code followed by the “flock mark” followed by a five digit number identifying the animal in question. There are rules as to the colour of the ear tags which can be used.

Where only one ear tag is used it should be fitted to the left ear of the animal.


Pigs must be identified by their herd mark before they are moved off a holding. The herd mark can be applied in one of the following ways:

  • by writing in permanent ink the herd mark on each front shoulder area of the pig (this is known as a “slapmark”);
  • by fitting a stamped or printed eartag to the pig which consists of the letters “UK” followed by the herd mark;
  • by tattooing the herd mark on the ear of the pig;
  • by painting with temporary paint a mark on the pig, which must last until the pig reaches its intended destination (this is only permitted for pigs under the age of one year old who are being moved to another holding).


It is a requirement that deer be tagged if they have been tested for bovine tuberculosis or before they are moved from their farm of origin. The tag should display their herd number followed by a unique number identifying the deer in question.


Horses cannot be moved without a “horse passport” except in certain circumstances, for example, where they are taken on a short hack.

Before a horse passport can be issued it will be necessary, in the case of foals and adult horses identified after 31 July 2009, to be implanted with a microchip identifying the horse or foal.