Deciding On An EID Tagging Convention – What’s The Right Choice For Your Sheep Farm?

Last year we were talking to a sheep farmer who told us their Breeding Objective was to breed sheep with bigger ears….They were using so many visual tags that they were running out of space to put in the various coloured management tags that they used to track their sheep. At risk of having a flock of sheep that would soon resemble a punk rock version of Dumbo, they were looking for a simpler way.

There is no doubt that the EID Tags are a fantastic tool to help sheep farmers avoid this issue. They allow all information to be stored electronically for the animal in a data recording software like BreedELITE, and provide so much more information that can be used for better decision making well before you get into the yards.

BreedELITE Sheep Software

The fundamental basis of precision sheep management is to have an individual record for each animal. The tagging convention is the next most important decision because it sets the rules for the way you store and recall each individual. Consistency is key, and tagging convention is no different.

If you don’t get this right you may feel like you are constantly fighting with your data or don’t quite get the level of simplicity that is possible, leading you to always changing the way you tag animals with it never being clear, and may end up back to wishing your sheep had bigger ears…

The good news is that it is pretty straight forward to land on a winning Tagging Convention for your farm that allows an integrated all-in-one system like BreedELITE to make your life super simple.

BreedELITE Sheep System

Before we start here are a few things to keep in the back of your mind as you decide which Tagging Convention is best for you:

  • Cost of tags vs cost of losing data on a sheep: Some Tagging Conventions will require a higher investment in tags, however this can quickly become insignificant if a lost or faulty tag means you lose the identity of a sheep after spending considerable cost and time collecting the data.
  • Labour availability: Some Tagging Conventions will allow more flexibility with certain management tasks and may save you labour. 
  • Ability to use EID tags across multiple years: This is not related to reusable tags (read which EID tags are right for you) but means that you use a generic coloured EID tag that has no year identifier. This prevents the need to purchase additional EID tags which can be 7x more expensive than visual tags and allows you to order your tags in bulk.
  • Cost of spare tags: When using NLIS EID tags you need to allow to purchase additional numbered tags to account for more lambs being born than expected as well as any retagging you may need to do over the life of the sheep. Whether the extra tags you need to hold are Visual Tags (cheap) or EID Tags (more expensive) can make a reasonable difference. For example, say you purchase 200 extra tags, this will cost you approx. $50 for Visual Tags vs $360 for EID Tags.
  • NLIS EID Tags will become compulsory in the future: Ok so this is not a guarantee but there is a very high chance that it will occur. When that happens you don’t want to be having to change your Tagging Convention.

Deciding on a Tagging Convention is the first and most important decision you need to make when starting with EID Tags. Unfortunately it is something that a lot of people struggle with and can lead to wasted effort and money, as well as a few headaches down the track. 

The right Tagging Convention for your flock will come down to your objectives with EID and data recording, what kind of operation you are running and the impact on your sheep farm if you lose the identity of a few sheep.

Key Principles

It is important to understand these key principles first:

What is a Unique Identifier and why do I need one?

A unique identifier is exactly as it sounds. It is a unique number that is allocated to an individual sheep on your property and is unique to that sheep. It is not repeated for any other sheep on your property or in your pedigree and performance recording software (e.g. BreedELITE Sheep). This means that if you have 20 years worth of sheep data then every sheep you have data for needs to have a unique identifier.

  • Option 1: The simplest Unique Identifier is to use is the following format: YY – XXXX (e.g. 21 – 0123, or sheep 123 of the 2021 year drop) or YY-XXXXXX (e.g. 21 – 010123 or sheep 10123 of the 2021 year drop) if you tag more than 9,999 sheep per year. RECOMMENDED
  • Option 2: A less practical alternative is to use the full 16 digit EID number (e.g. 951 00000123456). Note that anything less than the full 16 digits will not guarantee that the number is unique and WILL lead to problems at some stage.

If you have multiple breeds of sheep stored in the same version of the BreedELITE Sheep Software then the identifier needs to pick this up also. Even if the breeds of sheep are different they need a number that is unique as the computer doesn’t know that it is looking at a White Suffolk instead of a Poll Dorset. In a situation like this, we recommend starting each breed at a different thousand, for example my white suffolks start at 1 each year, and my poll dorsets start at 2001 each year. I reasonably expect to never have more than 2000 white suffolks in any one drop, so I should be able to keep this tagging convention into the future.

Definition: Lifetime Data vs Short Term Data

For the purposes of this discussion we will refer to lifetime data as information that you want to store against a sheep and then use beyond that management activity in the future. For example you may want to collect hogget fleece data and then record very little data in the future against that sheep, however you want to be able to access the data to make classing decisions later in that animals life. Alternatively short term data is recorded and then used for say less than a year before the sheep is sold or sent to market (common for Feedlot or Trading Sheep enterprises).

A Few Common Misconceptions…

Let’s deal with a few common misconceptions about EID tags and Tagging Conventions:

  • I can use the last 4 or 6 digits of the EID number as my unique identifier: It’s easy to see why this is done and you may get away with this for a while, but over the long term this always fails and you will end up with a double up. The only way to ensure the EID number is unique is to use the full 16 digits.
  • I will just put an EID Tag in and work it out later: working it out on the fly may get you started quickly, but changing to a different Tagging Convention later on can be costly and time consuming. It is worth spending a little time at the start to get clear on your end goals with your sheep data and ensuring you have appropriate record keeping and data management principles in place. BreedELITE can help you to get clear on this. Book a sheep technology audit now.
  • I have used other sheep software programs before and I didn’t need to worry about this: You can get away with not having a robust Tagging Convention with other software as linking together sessions and data collected on devices still requires you in the middle of it. The problem is you become the post processor to link data to animals and turn data into information, and the system is always reliant on your memory of what tags have changed forever. One of the key differences with BreedELITE is that all data is entered against the sheep in real time in the BreedELITE Sheep Software, instantly turning your data into information and completely removing you from the process. 
  • It’s easy to change later on: Changing tagging conventions midway through a year or after you have started can be difficult, costly and create more problems. If you are thinking about changing your tagging convention feel free to reach out to our team for assistance and to make sure it is going to suit your needs.
  • My data recording needs will stay the same: It is likely that as testing gets cheaper, and technology continues to improve or regulations change that you will want to collect more data. Picking a Tagging Convention that allows you future flexibility will make sure you don’t get caught.
  • I can use my left over number printed year tags again in 8 years: You will not be able to do this unless you omit these numbers from the tags you order otherwise there will be duplicate tags.

Now we have those out the way what is the best answer for your sheep farm?

Which Tagging Convention Is Right For Me?

In our experience, there are really only 4 options to choose from for your Tagging Convention. The 4 options fit under one of these two categories:

  • Single Tagging – 1 EID Tag
  • Double Tagging – 1 Visual Tag and 1 EID Tag (preferably in opposite ears)

If your sheep are only with you for the short term, like trading sheep or a feedlot then a simple Single EID Tag will be fine and there is no need to worry about your Tagging Convention (unless you are reusing EID tags). If you are breeding sheep (Commercial or Stud) for sale, self replacement or as seedstock then please read on.

To pick the right tagging convention for your farm there are three key questions you need to answer:

QUESTION 1: Lifetime (or Long Term) Data or Short Term Data only?

  • Do you want to have access to data for the lifetime of the sheep (Lifetime Data)?
    • IF NO – Short Term Data Only – ST Option 1 RECOMMENDED (refer ST Option 1 below)

QUESTION 2: Single vs Double Tag?

  • Are you ok with losing the lifetime data of one or more sheep? This is the same as saying the value of your sheep data isn’t worth having an insurance policy? 
    • IF YES – Single Tagging ST Option 2 RECOMMENDED (refer ST Option 2 below)
    • IF NO – Double Tagging – PROCEED TO QUESTION 3
  • NOTE: You may spend hundreds of dollars per sheep collecting data. A high performing sheep could be worth $100’s or $1,000’s more to your bottom line – the cost of an extra visual tag is a small price to pay as insurance in this instance.

QUESTION 3: Matching EID and Visual Tag or Generic EID and Visual Tag?

  • This really comes down to personal preference and the advantages and disadvantages discussed in the Double Tagging section below.
    • The cost of tags will vary between the two options
    • The simplicity of bulk tag entry using a bucket list varies between options
    • The labour required when tagging varies between options.
  • Refer Double Tagging section and decide what is right for you.

The 4 Options For Your Tagging Convention

Single Tagging (ST): 

A Single Tag System is by far the simplest way to identify your flock and will be suitable for the majority of sheep farms. The printing and colour options available allow you to have a single tag that is the EID, year colour, PIC and visual number all in one. 


  • Simple to implement
  • Cheapest option
  • Faster tagging
  • Bulk data entry via bucket list


  • Can’t use EIDs across years (as the printing will be 21-0001 for example so you need to keep them aside for replacements only for that year)
  • Only one form of identification, if the sheep loses its tag then all associated data is lost)
  • Need to purchase the correct number of tags each time so it is often done after lambing – unsuitable for early age stage measurements


  • ST Option 1: Generic commercial tag that has an EID number and PIC only (may be year colour coded but has no visual number printed)
  • ST Option 2: Single EID tag that includes year colour and has visual number printed on tag that aligns with the NLIS ID of the tag.

NOTE: We only recommend Single Tagging in Commercial or Feedlot operations. Stud animals should have two forms of ID in separate ears. They are just too valuable not to know which sheep is which.

Double Tagging (DT):

Double Tagging involves the use of an EID Tag and a Visual Tag. To minimise the risk of losing both tags it is best to place the tags in different ears. Both options give you a good level of insurance against losing the identity of the sheep as it is very rare to lose a tag from each ear.


  • Two forms of identification. Minimal risk of losing association of sheep data with an animal as there are 2 tags
  • Bulk data entry via bucket list (possible depending on selection) (DT Option 2 only)
  • EID’s can be purchased in bulk and don’t need to match the number of animals in the drop plus some spares (DT Option 1 only)
  • EID’s can be used across years (DT Option 1 only)


  • Slightly higher cost
  • Slightly slower and may require additional labour when initial tagging
  • Slightly more complex to implement (DT Option 1: need to associate Visual Tag number to EID in software; DT Option 2: Need to make sure the matching EID and Visual Tag are placed in the same sheep)


  • DT Option 1: Generic EID (no printed number) is associated with a non matching year coloured printed Visual Tag in the software when placed in the sheep
  • DT Option 2: Matching EID and Visual Tag pair is provided and matching tags are placed in the sheep

To explain this further, 

With DT Option 1 you can use a generic looking EID Tag, say a white EID tag. You can buy them in bulk and restock when they are running low as they can be placed in any sheep on your property. Often you will have your farm name printed on the top side of the EID tag. After the EID Tag is placed in the sheep you will need to manually associate the EID number with the visual tag number by scanning the sheep with the Smart Reader and then entering the visual tag number into the BreedELITE Sheep Software. 

HINT: There are handy presets in the software that means entering the visual number ’21-0001’ is as simple as typing ‘1’ or ’21-3000’ by typing ‘3000’. 

Whilst this is a slightly longer process when entering tags you have the advantage of a generic EID tag and end up holding spares of the cheaper visual tags. Each year you only have to buy the coloured visual tag (e.g. printed 21-0001 -> 21-3000) and associate when putting them in. 

For DT Option 2 you have the same number printed on the top of the EID as the visual tags, for example 21-0001 -> 21-3000. You then also order the visual tags with the same printing. They both come in strips of 10 and you have the job of sorting them out before tagging. You remove 21-0001 from both strips (EID and Visual Tags) at tagging time and place the pair into the sheep. In this case you can set up the Visual Tag number to be automatically entered to the software using the bucket file, saving you the additional labour and effort needed in DT Option 1. You can also choose to have the year colour on both the visual and EID tag, or if you have a generic EID colour. In this instance I recommend using the same colour for both in case they lose one of the tags. 

There is additional effort to sort the tags beforehand and additional care is needed to make sure the matched pair are placed in the correct sheep. This approach is less flexible for retagging but not inhibitive (i.e. if they lose one of the tags, then the printed visual number won’t match the replacement which can make searching a little harder, alternatively you need to hold more spare Visual and EID tags which is more expensive).

How To Save Money On Tag Printing

There are a multitude of different printing options above that we have discussed to suit all needs. One big advantage of the Datamars EID FET tags available through the BreedELITE buyers group is that in addition to the very good price, printing is absolutely free. They will also include your PIC number.

With free printing on the EID Tag vs 5c per side for the Visual Tags printing the property name on the EID tag rather than the Visual Tag can save you money.

The most common scenario we see with generic EID tags is to include the farm name on the top with a white EID tag and year coloured visual tag with the tag number which may or may not include the year suffix.

Conclusion & Quick Reference Guide

Our recommendation if you are collecting individual animal data on your sheep is to use DT Option 1 (Generic EID + Numbered Visual Tag) due to the cheap insurance of the additional visual tag and the ability to only buy the number of more expensive EID tags that you need.

If you are looking for the cheapest option available for your enterprise that will allow you flexibility in the future then use this quick reference guide:

Feedlot or Trading Enterprise

  • ST Option 1 – Single Non Printed (No Visual Number) NLIS EID Tag (cost around $1.35 + GST per sheep)

Commercial (no breeding nucleus)

  • ST Option 2 – Single NLIS EID Tag with printed visual number and year colour (cost around 1.35 + GST – printing FREE for BreedELITE Buyers Group members)

NOTE: Tags can only be used in the year of purchase and spare tags cant be used again in 8 years time as there will be double ups.

Stud or Commercial breeding nucleus

  • DT Option 1 – Visual Printed Tag with Year colour (this is your Unique ID for the sheep) with a Non Printed NLIS EID Tag in the other ear.

NOTE: Tag prices indicative only. Contact BreedELITE for a quote.

If you are considering changing your tagging convention this year then the most efficient time to do this is at lamb marking. 

If you would like to discuss this further or need help to find the best option for your sheep flock and specific circumstances please send us an email or give us a call. We are happy to help you nail this for your flock.