Cattle Ear Tags: Choosing a System, Applying, and Recording Them

Author: Elliott Garber, DVM

If you are deciding how to tag your cattle, start by choosing a tagging system, not a single product. The two questions that matter are: do you need official electronic identification for animals that will move interstate, and how are you going to manage your own herd numbers day to day. For most operations the answer is a combination: an official USDA “840” electronic tag (an EID button) for traceability, plus a large visual dangle tag carrying a management number you can read across the pen. As of 2025, the USDA requires that official ear tags used for the interstate movement of certain classes of cattle be both visually and electronically readable, so the electronic side of that pairing is no longer optional for those animals. This guide walks through the tag types, how the federal rule actually applies, how to apply a tag correctly and safely, and how to keep the numbers from getting lost once the tag is in the ear.

Know the tag types before you buy

Cattle ear tags fall into a few families, and most producers end up using more than one.

Visual dangle and panel tags are the plastic tags you picture when you think of ear tags. They carry a management number, and sometimes a name, that you assign for your own record keeping. Large panel tags are readable from a distance, which matters when you are trying to read a number across a crowded pen or from a truck. These are your everyday herd management tags. They are not official identification on their own, but they do the daily work of telling one animal from another.

Traditional metal clip tags are the small silver or orange metal tags that have been used for decades, historically for brucellosis (Bang’s) vaccination and for animals moving between states. The orange metal tag specifically marks a brucellosis vaccinate. These metal clips are being phased out as official identification in favor of electronic tags, as Michigan State University Extension and state agencies describe, but you will still see them in older animals.

Electronic tags (EID or RFID) store the animal’s number on a chip that a reader or wand can capture. The most common form is a low frequency (LF) RFID button tag worn on the inside of the ear, often paired with a visual tag on the outside. Ultra high frequency (UHF) tags also exist and can be read at greater distances, which some larger operations use for sorting and gate reads. The official version of the EID tag is the USDA “840” tag, covered next.

The USDA “840” tag and the traceability system

The official electronic identification tag for US cattle is the “840” tag. It carries a unique 15 digit number that begins with 840, the country code identifying the United States as the animal’s country of origin, and it is stamped with the US shield and marked “unlawful to remove.” That same 15 digit number is both printed on the outside of the button and stored on the electronic chip inside, which is what makes the tag both visually and electronically readable.

The 840 tag ties the animal into the national Animal Disease Traceability (ADT) system, which exists so that in a disease outbreak, animals and their contacts can be traced quickly. To order official 840 tags, you generally first register your location and obtain a Premises Identification Number (PIN) from your state animal health authority. The PIN ties the tags you apply back to your operation. Your state veterinarian’s office or a USDA accredited veterinarian is the right first call for getting set up, and USDA has been providing official tags to producers free of charge to encourage adoption.

What the 2025 federal rule actually requires

Here is the part that trips people up, so read it carefully. USDA APHIS published a final rule in the Federal Register on May 9, 2024, and it took effect on November 5, 2024, 180 days later. Under that rule, official ear tags applied to covered cattle and bison must be both visually and electronically readable to be recognized as official identification for interstate movement. In plain terms, a new official tag has to be an EID tag; a plain metal clip no longer qualifies as official ID going forward. Non-EID official tags applied before November 5, 2024 can remain official for that animal, so already-tagged animals do not all need retagging. Check with your state animal health office before replacing a tag.

The rule does not cover every animal. According to USDA APHIS and the American Veterinary Medical Association, the covered classes are sexually intact cattle and bison 18 months of age or older, all dairy cattle, and cattle and bison of any age used for rodeo, recreation, shows, or exhibitions, when those animals move interstate. Feeder steers going straight to slaughter channels, for example, are not swept in by these classes. This is a targeted rule, not a blanket “every cow needs an EID tag” mandate, and it applies to official identification for interstate movement. State rules can be stricter, so confirm your own state’s requirements with your state animal health official, and note that the rule has faced legal challenge, so check the current status before you rely on any summary.

How to apply an ear tag correctly

Application is where good intentions turn into torn ears and lost tags if the technique is sloppy. The single most important thing is placement.

Place the tag in the middle third of the ear, roughly two thirds of the way out from the head and centered between the two ribs of cartilage that run the length of the ear. The base of the ear, closer to the head, has thick cartilage that a tag will pinch, and the tip is where snag loss happens. The bovine ear has two large veins running from the head toward the tip; Merck Animal Health and university extension sources are clear that you must avoid piercing these veins to prevent bleeding, and avoid the cartilage ridges themselves, which can cause infection or deform the ear if pierced. Aim for the clear web of tissue between the ribs.

A clean, correct application looks like this:

1. Restrain the animal properly. Apply tags with the animal held in a head gate or chute, or otherwise properly restrained. This is a genuine hazard step: a swinging head can drive a pin into your hand or into the wrong part of the animal’s ear. Never tag a loose or moving animal.
2. Match the applicator to the tag and load it correctly. The male (pin) half and the female (button or panel) half must be seated properly in the applicator, with the studs aligned so they close cleanly. Load the male and female halves exactly as the tag maker specifies, orient the visual panel so the number reads correctly, and follow the tag instructions for whether the button or transponder sits on the inside or outside of the ear (backwards loading is a common mistake).
3. Keep it clean. Disinfect the applicator pin between animals, and keep the tags and pins out of the dirt. A contaminated pin is how you introduce infection into a fresh puncture.
4. Orient front to back and squeeze in one motion. Position the tag so it reads correctly, line up on the middle third between the ribs, and close the applicator in a single firm motion rather than a hesitant press.
5. Check that it swivels. After application, the tag should rotate and move freely. A tag pinched too tight against thick cartilage is painful and more likely to cause necrosis or tear out.

Watch tagged ears over the following days for swelling, heat, discharge, or a tag that has torn loose. Poor placement or a contaminated pin can lead to infection and, in bad cases, ear necrosis, where tissue around the tag dies. Anything beyond minor irritation is a call to your veterinarian, and any actual medical procedure around the ear should be left to or guided by a veterinarian.

Retention, readability, and keeping a backup

No tag lasts forever. Plastic visual tags fade in UV sunlight until the number is hard to read, and any dangling tag can snag on fencing, feeders, or brush and rip out. Electronic buttons are more retention friendly because they sit tight to the inside of the ear, but they can still be lost, and a dead or damaged chip reads as nothing. That is why running a backup identifier is common practice: an official 840 EID tag paired with a visual management tag, or a visual tag paired with a second permanent ID such as a tattoo or, where used, a microchip. If one is lost, you have not lost the animal’s identity.

The practical takeaway is that a tag is only as useful as the record behind it. The number in the ear points to an animal, but the value lives in what that number is connected to: the animal’s birth date, dam and sire, health and vaccination history, and its official EID.

Where the numbers actually live: your records

Whatever tagging system you choose, the tag number only earns its keep if it is recorded against the animal and stays with the herd’s records. A number on a faded tag with nothing behind it is worth very little at sale time or during a disease trace.

This is the part Creatures is built for. On each animal’s Creatures profile you can store its ear tag number, its EID or RFID, and its other identifiers together in one place, alongside pedigree, records, and photos, so the number and the animal never drift apart. Breed pages like Highland cattle sit on the same records layer, so a registered animal’s identifiers travel with its profile. When you sell, buyers browsing the cattle marketplace or finding you through the breeder directory are looking at an animal whose identity is documented, not just a tag color in a photo. Creatures is the records and marketplace layer around your herd, so the work you do at the chute keeps paying off.

Frequently asked questions

Do all my cattle need an electronic 840 tag now?

No. The federal EID rule applies to specific classes moving interstate: sexually intact cattle 18 months and older, all dairy cattle, and cattle used for rodeo, recreation, shows, or exhibitions. Many other animals are not swept in by the federal rule, though state rules can be stricter, so confirm with your state animal health official.

What is the difference between an 840 tag and a management tag?

An 840 tag is official USDA identification: a unique 15 digit number tied to the national traceability system, both printed and stored electronically, with the US shield. A management tag is a visual dangle tag carrying a number you assign for your own herd records. Most operations use both.

Where exactly should the tag go in the ear?

In the middle third of the ear, centered between the two ribs of cartilage, avoiding the large veins and the cartilage ridges. Too close to the head pinches thick cartilage; too close to the tip snags and tears out.

Can I apply tags myself?

Yes, producers routinely apply their own visual and EID tags with the animal restrained in a chute or head gate. Getting set up with official 840 tags usually starts with registering your premises for a PIN through your state animal health authority, and a veterinarian can help you order and get started.

How do I keep from losing track of a tag number?

Record the number against the animal as soon as you apply it, keep a backup identifier, and store the ear tag, EID or RFID, and other IDs on the animal’s profile so the number stays attached to its full history rather than living only on a plastic tag that can fade or fall out.

Do this next on Creatures

Whatever tagging system you run, the number is only useful if it is recorded against the animal. Creatures is the records, marketplace, and directory layer where the tag, the EID, and the rest of the herd’s history live in one place.