Pet microchips in the United States are registered with private recovery services. There is no single national database. The correct registry may be linked to the chip manufacturer, a shelter, a veterinary clinic or another registration service.
Having a chip implanted is not enough. The microchip number must also be linked to your current contact details.
This guide explains how to register a pet microchip in the United States, how to find the correct registry and what to do after an adoption, move or international journey.
Is pet microchipping required in the United States?
There is no single federal law that requires every privately owned dog or cat in the United States to be microchipped.
However, state, county and city rules can differ.
Some local authorities may require microchipping in certain situations. Shelters and rescue organisations may also require it before adoption.
Local pet licensing is separate from microchip registration.
Your dog may need both a microchip registration and a city or county licence.
Ask your veterinarian or local animal-control service which rules apply where you live.
Implanting and registering are different steps
A microchip contains a unique identification number.
It does not store your name, address or telephone number.
Those details are kept by a separate microchip registry.
Implanting the chip means placing the microchip beneath the animal’s skin.
Registering the chip means linking its number to the pet and your contact details.
A chip may scan correctly but still provide no route to the owner when the registration was never completed.
Our guide How to Register a Pet Microchip explains the general process in more detail.
Where are pet microchips registered in the United States?
The United States uses many private microchip registries.
Some are operated by microchip manufacturers. Others are independent pet-recovery services.
The clinic, shelter, breeder or rescue that supplied the chip may have started the registration for you.
In other cases, the owner must complete the registration online or by telephone.
Never assume that the chip was registered automatically.
Do US states have their own microchip registries?
Usually, no.
The United States does not normally use one official microchip registry for each state.
Most chips are registered with private pet-recovery services.
Some counties, cities or animal-control departments also keep local microchip records.
These records may be linked to:
- Pet licensing
- Animal-control services
- Local shelters
- Municipal lost-pet systems
A local record can be useful, but it should not replace registration with a reliable microchip registry.
The main registry should be easy to find through a national lookup service such as the AAHA Microchip Registry Lookup.
When you move, update your private microchip registration.
Also check whether your new city or county requires a pet licence or keeps its own local microchip record.
How do I find the correct registry?
Start with any documents you received when the chip was implanted or the pet was adopted.
The registry name may appear on:
- The microchip certificate
- Veterinary records
- Adoption paperwork
- Breeder documents
- A registration email
- A payment receipt
When you do not know the registry, use ChipTrace or the AAHA Microchip Registry Lookup.
AAHA’s Microchip Registry Lookup checks participating registries and shows which companies may hold information for the chip.
It does not display the owner’s private details.
It tells you which registry should be contacted.
AAHA does not register chips or update owner records itself.
How to register a pet microchip in the United States
- Confirm the microchip number.
Ask a veterinarian or shelter to scan the pet when you do not have reliable paperwork. - Find the current registry.
Check your documents, search with ChipTrace or use AAHA’s lookup tool. - Contact the registry.
Use its official website or telephone number. - Create or claim the record.
The registry may ask you to create an owner account. - Enter the pet’s details.
Add the name, species, breed, sex, colour and other requested information. - Add your contact details.
Include a current telephone number, email address and home address. - Provide proof when requested.
An adoption contract, transfer form or veterinary record may be needed. - Pay any required fee.
Some registrations are free. Others charge a one-time or recurring fee. - Keep the confirmation.
Save the registry name, account details and registration reference.
What details will the registry need?
The exact requirements depend on the registry.
You will usually need:
- The full microchip number
- The pet’s name
- The species and breed
- The pet’s sex and colour
- Your full name
- Your telephone number
- Your email address
- Your home address
You may also be asked for:
- An emergency contact
- The veterinary clinic
- An adoption contract
- A transfer code or form
- Proof of ownership
- A photograph of the pet
How do I know whether the registration is active?
Do not stop after submitting the form.
Check that you received confirmation from the registry.
Make sure:
- The microchip number is correct
- Your telephone number works
- Your email address is current
- Your home address is complete
- The pet’s details are correct
You can also search the number through ChipTrace or AAHA’s lookup tool.
A result may show the registry without displaying your personal details.
That is normal.
What is the AAHA Microchip Registry Lookup?
AAHA stands for the American Animal Hospital Association.
Its free lookup tool searches participating microchip registries.
Enter the microchip number without spaces or punctuation.
The tool may show:
- A registry holding the record
- More than one possible registry
- The most recently updated registry first
- A manufacturer or distributor when no owner registration is found
The tool does not:
- Show the owner’s private information
- Register a chip
- Update an existing record
- Search every registry in the world
When several registries appear, contact the first one listed.
Continue down the list when needed.
Does the chip have to be registered with its manufacturer?
Not always.
A chip is often first registered with the service linked to its manufacturer or distributor.
However, some owners also use an independent registry.
The most important point is that the chip appears in a reliable service that:
- Can be found through common lookup tools
- Maintains current contact details
- Responds when a lost pet is found
- Allows owners to update the record
Keep a note of every registry in which the chip is active.
Can a chip be registered in more than one database?
Yes. A chip number can appear in more than one registry.
An additional record can give a finder another way to reach you.
This may help when:
- The pet travels internationally
- The original registry becomes unavailable
- A finder uses a different lookup service
- The first registry has outdated information
However, multiple records can cause confusion when the details do not match.
Use the same current contact information in every active registry.
Can I add an international registration?
Yes. An international record can provide an extra route back to you.
Animal-ID allows owners to add an existing microchip number to a global database.
This can be useful when a pet travels or moves outside the United States.
An international registration should support the main US record.
It should not replace it.
How do I transfer a microchip after adoption?
Do not assume that the registry changes the owner automatically.
Ask the shelter or rescue for:
- The full microchip number
- The registry name
- The current registration status
- A transfer form or code
- Written confirmation of the adoption
Some organisations submit the transfer themselves.
Others expect the adopter to complete it.
Check the registry after the adoption.
Make sure your own details appear on the record.
What if the previous owner is still registered?
Contact the registry and explain the situation.
It may ask for:
- An adoption contract
- A signed transfer form
- A purchase agreement
- Veterinary records
- Proof that you tried to contact the previous owner
- Other proof that the animal is now in your care
Do not create false details or claim ownership without evidence.
When ownership is disputed, contact the registry, shelter, veterinarian or local authority for advice.
What happens when I move to another state?
You normally do not need to change microchip registries simply because you move to another state.
Update your existing record with:
- Your new address
- Your current telephone number
- Your current email address
- A new emergency contact when needed
Also check the pet-licensing rules in your new city or county.
Local licensing and microchip registration are separate systems.
What if the registry closes?
A microchip does not stop working when a registry closes.
However, the owner record may no longer be available through that company.
Ask a veterinarian to scan the pet and confirm the number.
Then:
- Search the number through ChipTrace or AAHA
- Check whether another registry holds a record
- Register the existing chip with a reliable active service
- Keep the new confirmation
The chip does not normally need to be removed or replaced.
What if no registration can be found?
A missing result does not always mean the chip is invalid.
Possible reasons include:
- The chip was implanted but never registered
- The number was copied incorrectly
- The registry does not participate in the lookup service
- The record is very recent
- The registry is temporarily unavailable
- The registry has closed
- The pet was registered in another country
Our guide Why Can’t I Find a Microchip in Any Database? explains these possibilities in more detail.
Ask a veterinarian to scan the animal again and confirm every digit.
ChipTrace may still identify the manufacturer, distributor or another useful contact.
Does a US microchip number begin with 840?
Not always.
840 is the ISO numeric country code for the United States.
Some authorised US country-coded chips may begin with 840.
Many chips used in the United States begin with a manufacturer code instead. These codes start with the number 9.
The first three digits alone do not prove that the pet is American or registered in the United States.
The full number must be checked.
See Pet Microchip Numbers Explained for more information about country and manufacturer codes.
Can an imported pet keep its foreign microchip?
Usually, yes.
A readable chip does not normally need to be replaced simply because the pet moves to the United States.
Ask a veterinarian to:
- Scan the animal
- Confirm the full chip number
- Check that the chip can be read with a suitable scanner
- Record the number in the US veterinary file
Keep the foreign registration active when possible.
Update it with your US contact details.
You can also create a US registration for the existing chip.
What are the US requirements for imported dogs?
US entry rules for dogs are separate from ordinary microchip registration.
All dogs entering or returning to the United States must:
- Appear healthy on arrival
- Be at least six months old
- Have a microchip that can be read with a universal scanner
- Travel with a CDC Dog Import Form receipt
Dogs that have been in a country with a high risk of dog rabies during the previous six months need extra documents.
Check the current CDC dog import requirements before travelling.
The microchip number must match the number on the travel documents.
For some rabies documents, the chip must have been implanted before the rabies vaccination was given.
Travelling abroad from the United States
Every destination country has its own pet-entry rules.
Some require:
- An ISO-compliant microchip
- A rabies vaccination given after the chip was implanted
- A rabies blood test
- A veterinary health certificate
- USDA endorsement
- An import permit or advance notice
Use the USDA APHIS Pet Travel website to check the current requirements.
Contact a USDA-accredited veterinarian as early as possible.
How do I update my contact details?
Contact the registry that holds the record.
Update it after:
- Moving home
- Changing your telephone number
- Changing your email address
- Changing the emergency contact
- Adopting or rehoming the pet
- Moving to another country
Check the record at least once a year.
An old telephone number can prevent a finder from reaching you.
What should I do if my pet goes missing?
Contact the microchip registry as soon as possible.
Ask it to mark the animal as missing.
Also contact:
- Local shelters
- Animal-control services
- Veterinary clinics
- Rescue organisations
- Local lost-pet groups
Do not publish the full microchip number in public posts.
Keep it private so it can help confirm ownership.
Someone who finds your pet can follow Found a Microchipped Pet? What to Do Next.
US microchip registration checklist
- Ask a veterinarian to scan the chip
- Confirm the full microchip number
- Find the current registry
- Complete the owner registration or transfer
- Keep the confirmation
- Check your telephone number and email address
- Update the record whenever you move
- Check local pet-licensing rules separately
- Keep useful foreign records active
- Consider an additional international registration
Check a US pet microchip
Enter the complete microchip number in ChipTrace.
ChipTrace searches connected registries and lookup services.
When no registration is found, it may still provide manufacturer information and useful next contacts.