Q&As - Livestock Identification Tag Prefix Code

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Questions and Answers relating to the change to the Northern Ireland prefix code on livestock identification tags.

(Updated 30 June 2025)

The prefix code on Northern Ireland livestock tags has changed from ‘UK’ to ‘XI’.
From 30 June 2025 it is a mandatory requirement to identify all newborn livestock in Northern Ireland with ‘XI’ prefixed tags.
Unused stocks of ‘UK’ prefixed tags are now obsolete, and keepers should dispose of them, as they will not be able to use them to identify their animals.

Question – Why did tags have to change?
Answer – It is a legal requirement under the European Union Animal Health Law (AHL), Regulation (EU) 2016/429, which applies in Northern Ireland (NI), that the prefix code on NI livestock identification tags should be 'XI'.

The introduction of ‘XI’, ensures that DAERA is in compliance with its legal obligations, and has allowed for continued unfettered access to both the EU and UK domestic markets, subject to existing export eligibility requirements. Using ‘XI’ also ensures the continued operation of a legally compliant traceability system, which is the fundamental cornerstone of the Northern Ireland agri-food industry and essential to the protection of trade, public health, animal health and welfare.
Question – What has changed?
Answer – On 24 June 2024, the prefix code on Northern Ireland (NI) livestock identification tags (cattle, sheep and goats) changed from ‘UK’ to ‘XI’, and only ‘XI’ tags have been available to purchase from then.
Question – Why has the digit after the 'XI' prefix on cattle tags also changed?
Answer – To facilitate the possible introduction of bovine electronic identification (EID) in the future, there has been a minor change to the numbering format on cattle tags. The digit 0 has replaced the digit 9 in front of the herd number on cattle tags.
Question – Can keepers continue to use 'UK' tags?
Answer – From Monday 30 June 2025 only ‘XI’ prefixed tags can be used to identify newborn cattle, sheep and goats. Since that date unused stocks of ’UK’ prefixed tags are obsolete and should be disposed of.
Question – What has the change meant for cattle tags?
Answer – Physically tags look the same as before. All new cattle tags issued in NI begin with ‘XI’ 0, replacing ‘UK’ 9, while the remaining numbers on tags are unchanged. After the ‘XI’ 0 prefix, all numbers are as currently formatted:
- Natal 6-digit herd number;
  - 4-digit individual animal number; and
  - A check digit*
Tags will carry on in sequence from the last number issued to your herd prior to changeover. For example:

If the last UK 9 tag issued to you was:
UK 9 123456 1234 5*

The next newly issued tag will be:
XI 0 123456 1235 6* (*Check digit changes and will depend on formula)
Question – What has the change meant for sheep tags?
Answer – As with cattle, physically tags look the same as before. All new sheep tags begin with ‘XI’ replacing ‘UK’, while the remaining numbers on tags are unchanged. After the ‘XI’ prefix, all numbers are as currently formatted:
- The digit 1
  - The 6-digit natal flock number
  - The 5-digit individual animal ID
Tags will carry on in sequence from the last number issued to your herd prior to changeover.

If the last UK 1 tag issued to you was:
UK 1701234 56789 (EID 826 1701234 56789)

The next newly issued tag will be:
XI 1701234 56790 (EID 899 1701234 56790)
Question – What has the change meant for goat tags?
Answer – As with cattle and sheep, physically tags look the same as before. All new goat tags begin with ‘XI’ replacing the ‘UK’, while the remaining numbers on tags are unchanged. After the ‘XI’ prefix, all numbers are as currently formatted:
- The digit 1
  - The 6-digit natal flock number
  - The 5-digit individual animal ID
Tags will carry on in sequence from the last number issued to your herd prior to changeover.

If the last UK 1 tag issued to you was:
UK 1701234 56791 (EID 826 1701234 56791)

The next newly issued tag will be:
XI 1701234 56792 (EID 899 1701234 56792)
Question – What about EID tags on sheep and goats?
Answer – No issues have been identified as a result of changing to the ‘XI’ prefix for EID tags on sheep and goats. ‘899’, the 3-digit numerical equivalent of ‘XI’ for NI livestock ID purposes, is encoded on EID devices in the same way ‘826’ is currently encoded as the equivalent to ‘UK’.
Keepers who read sheep and goat tags using an EID reader and upload the tag numbers to a farm software package should confirm with their providers that their software is compatible with the ’XI’ prefix.
Question – Have the requirements for Sheep and Goats CPRs changed?
Answer – Central Points of Recording (CPRs) such as marts, abattoirs and Export Assembly Centres (EACs) have made the necessary changes to their systems to accommodate the ‘XI’ prefix. CPRs read sheep and goat tag numbers and upload movement notifications to the Animal and Public Health Information System database (APHIS) electronically. CPR software translates ‘826’ on sheep and goats EID tags to ‘UK’ before uploading movement notifications to APHIS. CPR operators have amended their software to ensure that their software also recognises ‘899’ when reading sheep and goat EID tags in the new format and translates this to ‘XI’ before upload.

Depending on when tags were issued, there will be livestock in circulation for the foreseeable future identified either with ‘UK’ or ‘XI’ prefix codes and both will be accepted as forms of identification, valid at the time of application. Sheep and goats could be presented at CPRs with ‘XI/899’ tags, as well as animals tagged with old ‘UK/826’ tags, so software is able to read and translate both.
Question – Do farmers need to apply ‘XI’ tags to all their existing herd/flock?
Answer – No, there is no requirement to re-identify all livestock previously identified with ‘UK’ prefixed tags if they will remain within the UK.
However, if you plan to export animals to continental Europe, these tags must be replaced with 'XI' tags prior to export to prevent the animals’ ID numbers being deemed ineligible. (See Q. 13).
For exports to Ireland all sheep and goats should be reidentified with XI tags, however, there is no need to reidentify cattle (see Q 14).
If re-identifying cattle with 'XI' tags this must be done under DAERA or OV/OVI supervision and correlated on NIFAIS prior to export.
If re-identifying sheep and goats with 'XI' tags prior to export, this can be done by the keeper themselves and correlated in the flock register.
If you wish to export livestock to Europe including Ireland , and there is any reason you believe makes it not possible to re-identify your animal, such as pedigree registration, contact the DAERA Trade Export team via email: daeratradeexports@daera-ni.gov.uk for further advice.
Question – Do farmers need to apply an ‘XI’ tag to animals when replacing an original ‘UK’ tag which has been lost or damaged?
Answer – If an animal was tagged at birth with a double set of ‘UK’ 9 prefix tags (cattle), and loses a tag in one ear, the keeper should order a replacement tag as normal from their tag supplier. The replacement tag will be exactly the same as the original tag, even if ordered after 30 June 2025.

For example, if an animal was identified at birth on 01/03/2023 with tag number UK 9 123456 1234 5, and the keeper notices one tag missing and orders a replacement on 01/11/2024, the replacement tag will also read:

UK 9 123456 1234 5
Question – What happens if an animal needs to be re-identified?
Answer – There are no plans to require the re-identification of all animals previously identified with ‘UK' prefix tags, with ‘XI’ tags, if the animals will remain in the UK. Re-identification, however, is required for all animals with ‘UK’ prefixed tags being exported to continental Europe (see Q 13), and for all sheep and goats being exported to Ireland (see Q 14).
If an animal has to be re-identified for any other reason it can only be re-identified using a ‘XI’ prefixed tag.
Example – lost cattle:
If a bovine animal has lost both sets of original 'UK' tags, or it is a GB import, it will be identified with an entirely new number, as happens currently, it may or may not be possible to correlate with its old 'UK' 9 number.
E.g. - A bovine animal was tagged at birth on 01/03/2023 with tag number: UK 9 123456 1234 5, and it was discovered on 01/07/2025 to have lost both its ear tags, it will be issued with new tags in the format: XI 0 123456 1987 6.
Question – What is required to export animals to the European Union (EU)?
Answer – EU Animal Health Law requires the use of 'XI' tags as the official identifiers. Therefore, any animals identified with 'UK' tags that are being exported to continental Europe, must have them replaced with ‘XI' tags prior to export (see Q. 12 for further details). This will prevent the animals’ ID numbers being deemed ineligible.
If you have questions regarding exporting animals to Europe, information can be found on the DAERA Exports webpage.
For further questions please contact the DAERA Trade Export team via email: daeratradeexports@daera-ni.gov.uk
Question – What is required to move animals to Ireland?
Answer – From 30 June 2025, all sheep and goats must be identified with the ‘XI' tags prior to their export. Any such sheep and goats previously tagged with 'UK' tags must be re-identified with ‘XI’ tags.
Cattle identified with ‘UK’ tags prior to 30 June 2025 can still be exported to Ireland after this date without being re-identified with ‘XI’ tags.
Question – What is required to move animals to Great Britain (GB)?
Answer – Livestock to be moved from NI to GB, must be officially tagged with either ‘UK’ or ‘XI’ prefixed tags. DAERA consider such animals to have full traceable IDs for domestic movement purposes.
Question – How can farmers ensure their pedigree sheep can be traced to their original 'UK' identification, following re-identification with 'XI' tags for export to the European Union (EU)?
Answer – For pedigree sheep which are re-identified with 'XI' tags for export to Europe (see Q.13), purchasers may wish to have a visible link to the old 'UK' tag number. Keepers have the option to apply the following measures which will assist with animal traceability:
- Keeper removes the 'UK' prefix EID tag, leaving only the visual 'UK' prefix tag in place;
  - Keeper applies the new 'XI' tags, which become the animal's official identification, under which the animal will move in future, both domestically and for export;
  - The old 'UK' tag, which remains on the animal, will essentially become a management tag;
  - Keeper correlates each 'XI' tag number applied with the old 'UK' number in their flock register (NIFAIS Online Users can correlate the re-identification on the Department's database);
  - Keeper notifies the relevant breed society of the re-identification;
  - If satisfied with the information supplied by the keeper, the breed society will correlate the re-identification in their flock records and supply new zootech certificates if required.
If you have any questions on exporting pedigree sheep to Europe, contact the DAERA Trade Export team via email: daeratradeexports@daera-ni.gov.uk for further advice.
Question – How can farmers maintain the pedigree registration status of their sheep, following re-identification with 'XI' tags for export to the European Union (EU)?
Answer – Where a keeper re-identifies pedigree sheep with 'XI' tags for export to Europe (See Q. 13), and they wish to retain the pedigree registration status of those sheep, they should advise the relevant breed societies in the first instance. Provided keepers notify the relevant breed society of the re-identification, and the breed society is satisfied with the correlation between the old 'UK' tag number and the new 'XI' tag number, most breed societies should be able to correlate the re-identification in their pedigree flock registers and supply keepers with new zootech certificates if required.
Breed societies should then report any correlated re-identification to DAERA, via email: DAERA.ImplementationSupportUnit@daera-ni.gov.uk
DAERA staff will move the old 'UK' prefix tag numbers to 'suspense'. This will ensure that the animal can no longer be moved under its old 'UK' tag number.
Question – Will NI livestock still be classified as United Kingdom (UK) origin?
Answer – There has been no change to the status of NI livestock or how they are classified, as they still originate from NI as part of the UK. ‘XI’ is only a code on livestock tags to allow animals to be appropriately identified and to be traced to their holding of origin in NI.
Question – Will farmers need to switch from ‘UK’ tags to ‘XI’ tags on other species?
Answer – There are not currently any plans to switch to the ‘XI’ tags for species other than cattle, sheep and goats.

In future, it will be a requirement to identify Camelid and Cervid animals, such as alpacas, llamas and deer, with a form of identification bearing the code ‘XI’. This is not a change to existing forms of identification, but rather a new requirement to have these animals identified as per the requirements of the AHL.
Question – What about remaining stocks of tags bearing the ‘UK’ prefix from 30 June 2025?
Answer – All unused ‘UK’ prefix tags held by livestock keepers are now obsolete and should be disposed of, as they cannot be used to identify newborn animals.
Question – Will compensation be available for stocks of old tags bearing the ‘UK’ prefix?
Answer – There is no compensation available for obsolete tags.

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Q&As - Livestock Identification Tag Prefix Code