APHIS	 Factsheet

Veterinary Services August 2006

National Animal 

Identification 

System: Animal 

Identification 

Number (AIN) Tags

In 2004, the U.S. Department of Agriculture’s (USDA) 

Animal and Plant Health Inspection Service (APHIS) 

announced the implementation of the National Animal 

Identification System (NAIS). The NAIS is a voluntary, 

cooperative Federal–State–industry program, providing a standardized information system for Federal and 

State animal-health authorities to use in responding 

to animal-disease events in the United States. The 

NAIS has three components: premises registration, 

animal identification, and animal tracking. Premises 

registration is ongoing. APHIS has recently approved 

manufacturers of NAIS animal tags allowing producers 

to participate in the second component of the NAIS. 

Basic Requirements of AIN Tags

All AIN tags are:

• Designed for one-time use and tamper evident, 

• Unalterable, 

• Able to be read at a distance of 30 inches, and

• Able to remain on an animal for the duration of its 

life.

Basic Characteristics of AIN Tags

AIN tags have several other distinguishing characteristics. They are imprinted with:

• An animal identification number that is a unique 15

digit number starting with 840 (the country code 

for the United States),

• The U.S. shield ,

• The term “unlawful to remove,” and

• The manufacturer’s logo or trademark.

Tags with button front and button back pieces 

must have the above information printed on the piece 

that, when applied, is on the outside of the animal’s 

ear. This piece is commonly referred to as the “back” 

of a two-piece tag. By having the imprinted information on the back, it will make visual reading easier.

The de-facto standard for some species is a 

visual eartag. If a tag meets the imprinting criteria 

listed above, it may have radio frequency identification (RFID) technology encased in the visual tag. This 

technology is considered supplemental identification, 

since the visual tag remains the animal’s official identifier. If a tag contains RFID technology, it must have 

all 15 digits of the AIN printed on the tag piece that 

contains the transponder. 

How To Obtain an AIN Tag and When To Apply It

In order to obtain AIN tags, producers must first register their premises and obtain a premises identification number (PIN). This requirement exists because 

all AIN tags are linked to a producer’s PIN in the AIN 

management system. Premises registration is currently free and is being carried out by all 50 States, 

two territories, and five tribes. A list of State and 

tribal animal identification coordinators is available at 

<http://www.usda.gov/nais>, under the sidebar “Contact Your State or Tribe.”

Once producers have registered their premises, 

they may purchase AIN tags from an AIN tag manager 

or reseller. Only AIN tag managers and resellers are 

authorized to provide AIN devices for producers. Producers should contact authorized AIN manufacturers 

for the AIN tag managers and resellers in their area. 

A list of AIN manufacturers is available at 

<http://nais.aphis.usda.gov/ainmngt>. Click on the 

“List ID Devices” in the left sidebar. Authorized AIN 

tags will have “NAIS” listed in the “Approval Status” 

column.

Since the AIN tag is referenced to a PIN, producers should take care not to transfer their tags or make 

them available to other producers.

Producers may attach the AIN tags at their convenience and at the time most suitable to their operation, 

but before an animal leaves their premises.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, 

national origin, age, disability, and where applicable, sex, marital 

status, familial status, parental status, religion, sexual orientation, 

genetic information, political beliefs, reprisal, or because all or part 

of an individual’s income is derived from any public assistance 

program. (Not all prohibited bases apply to all programs.) Persons 

with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) 

should contact USDA’s TARGET Center at (202) 720–2600 (voice 

and TDD). To file a complaint of discrimination, write to USDA, 

Director, Office of Civil Rights, 1400 Independence Avenue, S.W. , 

Washington , D.C. 20250–9410 , or call (800) 795–3272 (voice) or 

(202) 720–6382 (TDD). USDA is an equal opportunity provider and 

employer. 

United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture