Every newborn calf must have an ear tag in each ear showing the same unique identity number. The number is make up of a herd mark and an identity number.

Calves must be tagged with the following deadlines:

• Dairy farmers: you must fit 1 ear tag within 36 hours of a calf’s birth. You are allowed up to 20 days from birth to fit the second tag.
• Beef farmers: you have up to 20 days from birth to fit both tags

Both tags must be fitted before the animal moves off the holding of birth.

The tags used for double tagging are known as primary and secondary tags.

• The ‘Primary’ tag may be put in either ear. Primary tags are yellow, distance-readable tags – Large or Medium
• The ‘Secondary’ tag must have the same information as the primary tag, but may also contain management information. The secondary tag must be in the other ear from the primary tag – Large, Medium or Button

You must replace lost or illegible tags as soon as possible but no later than 28 days after you notice the loss or damage.

Animals born or imported after 1 January 1998 must keep their unique identity for life. So lost tags must be replaced with another tag showing the same identification number.