Your dog's microchip: ISO standards abroad

Your dog’s microchip has to meet two international standards, ISO 11784 and ISO 11785, so that a vet, an airline or a border officer abroad can actually read it. A compliant chip is usually 15 digits long. If your dog’s chip is not compliant, the US authorities ask you either to carry a scanner that can read it or to have a second, compliant chip implanted, and the British government warns that you may have to bring your own reader.

Which standard must your dog’s microchip meet?

ISO 11784 and ISO 11785. USDA APHIS, the animal health service of the US Department of Agriculture, states on its page for pet travel to France that ISO-compliant microchips are usually 15 digits long and meet the ISO 11784 and 11785 standards. The British government asks for the same thing for entry into Great Britain: the chip must meet International Organization for Standardization standards ISO 11784 and ISO 11785.

On the European side, the standard is not named by number. The European Commission says the pet must be identified by the implantation of a microchip and points to the technical specifications in Article 70a, point (a), of Commission Delegated Regulation (EU) 2019/2035, as amended. We were unable to open that text while preparing this article, so we do not reproduce its contents here.

In the United States, ISO compliance appears in black and white in the CDC’s own paperwork. The federal health agency’s Certification of Foreign Rabies Vaccination and Microchip form has a field for the “ISO-COMPLIANT MICROCHIP NUMBER”, and the veterinarian who signs it certifies having verified the presence of an ISO-compliant microchip in the animal.

What do the 15 digits of a microchip number mean?

They read as blocks, and the first block gives the country. The French national pet identification database, run by the company I-cad under delegation from the Ministry of Agriculture, sets out how the unique 15-digit code is built:

• 3 digits for the country code, 250 for France;
• 2 digits for the species, 26 for dogs and cats;
• 2 digits for the chip manufacturer’s code;
• 8 digits for the animal’s own identification number.

That number is the one you will find on your dog’s EU pet passport, on its health certificate and on entry forms. The European Commission requires the alpha-numeric code displayed by the microchip or the tattoo to be documented in the dog’s paperwork.

The chip itself is described by I-CAD as a small cylinder about 1 mm across and 3 to 4 mm long, placed under the skin without anaesthetic by a vet. It is waterproof and biocompatible, contains no magnetic or electrical system, and a specific reader is needed to read it. In other words, without the right reader the number stays out of reach. That is what the rest of this article is about.

Will your dog’s chip be readable abroad?

Only if it is compliant, or if you bring the right reader. This is the most commonly overlooked part of a travel file, and the three authorities we consulted all handle it the same way.

In the United States, the CDC writes that your dog’s microchip can be any brand, but it must be detectable with a universal scanner. It adds a concrete warning: if the chip number starts with a digit other than 9, check with your veterinarian that it is readable. The requirement applies to every dog, including those arriving from a dog-rabies free or low-risk country.

In the United Kingdom, GOV.UK is explicit: if your pet’s microchip does not meet ISO standards, you may have to bring your own microchip reader when you travel, and you should check with your travel company before you leave.

For the European Union, the USDA spells out what to do when a working chip is not ISO-compliant: travel with a scanner that can read it, or have your vet implant a second, ISO-compliant chip. In that case both numbers must be listed on the health certificate.

What happens if the chip cannot be read on arrival?

The dog can be refused at the border. The CDC puts it plainly: if the microchip cannot be scanned on arrival for a dog that has been in a high-risk rabies country, the dog may be denied entry and returned to the country of departure at the importer’s expense. For those dogs, the chip number must also be listed on all required documentation.

It helps to know when the check actually happens. The CDC tells airlines they do not need to scan dogs for microchips: they only verify that the dog has a chip and, for a dog coming from a high-risk country, that the CDC Dog Import Form receipt lists its chip number. The chip may not be physically scanned until arrival, in front of the US authorities. An unreadable chip therefore clears boarding without trouble and stops the journey at the far end.

Two simple habits cut that risk. Ask your vet to scan the chip in front of you at the pre-travel appointment, and keep the number somewhere other than the passport, on your phone for instance. Our guide to what to pack for your dog covers the documents to carry.

Does the chip have to come before the rabies vaccination?

Yes, and the order of the two decides whether the vaccination counts. The European Commission sets the rule for entry into the EU: the date of administration of the vaccine must not precede the date of identification or reading of the microchip. Its travellers’ page says the same thing in one line: the pet must carry a microchip before the vaccination for the vaccination to be valid.

The USDA turns this into a practical instruction for vets: they must always scan the microchip before giving a rabies vaccination, because a vaccination given without the chip being scanned first does not count under EU rules.

The CDC applies the same principle to entry into the United States: the microchip must be implanted before the dog gets its rabies vaccine, or else the vaccine will be invalid. The British government accepts a chip implanted before or at the same time as the rabies vaccination, and warns that otherwise the pet will need to be vaccinated again.

The consequence is expensive in time: an invalidated vaccination has to be repeated, and the waiting period that follows starts again from zero. The British government only allows entry at least 21 full days after the first vaccination. It is one of the costliest mistakes in a travel file, as we explain in The EU pet passport for dogs and Rabies antibody test for dogs.

Can a tattooed dog still travel?

Yes, provided the tattoo predates 3 July 2011 and is clearly readable. The European Commission allows the movement of dogs identified by a clearly readable tattoo applied before 3 July 2011, and the French Ministry of Agriculture confirms that animals tattooed before that date are exempt from the microchip requirement for travel. The tattoo is applied as letters and figures on the inner surface of the ear flap.

Chips already in place stay valid. For movements between EU countries, the Commission accepts a chip inserted in accordance with Article 17 and Annex II of Regulation (EU) No 576/2013 before 22 April 2026. So there is no need to re-chip a dog identified years ago.

Watch the legibility condition, which the Commission states explicitly: the tattoo must be clearly readable. Once it no longer is, it no longer does its job, and a chip becomes the only option. Have your vet check it well before departure, not in the week of the flight.

At what age is a microchip compulsory in France?

Before four months of age. The Ministry of Agriculture states that, for dogs, identification must be carried out before the age of 4 months. The chip, the size of a grain of rice, is injected under the skin by an authorised professional, usually the vet at a first appointment.

Identification is worthless if the database is out of date. The records are held in the national file run by I-cad under delegation from the Ministry, and it is up to the keeper to report a change of address or phone number. A chip read abroad that leads to an abandoned phone number will not bring your dog back to you.

For travel, the Ministry is clear: identification by microchip is compulsory for the European Union and for many other countries. The conditions for each destination are gathered on our travel requirements pages, in particular for the United States and the United Arab Emirates.

Who checks your dog’s microchip before a private flight?

At Loulou Air, our brokers do: they check every dog’s file before departure, chip number included. Travel requirements still apply on every flight, private ones included, so a private jet does not remove the need for a compliant chip, a valid rabies vaccination or the form the destination country asks for. Loulou Air is a brand of AEROAFFAIRES, a private aviation broker since 1991, and sells Pay-per-Seat private jets for your dog and you: you pay for your seat, not the jet, and each ticket covers one seat for a human and their dog. On board, your dog travels in the cabin with you, at your feet for the whole flight and never in the hold, with none of the weight limit imposed by scheduled airlines. Our flights serve New York, Dubai and Los Angeles: see the open flights. For anywhere else, we open new routes every month, so talk to a broker about the trip you are planning.

Frequently asked questions

How do I know whether my dog’s chip is ISO-compliant?

Ask your vet, who can scan it during an appointment. The USDA says a compliant chip is usually 15 digits long and meets the ISO 11784 and 11785 standards. The CDC advises checking readability with your veterinarian when the chip number starts with a digit other than 9.

Can a dog be given a second microchip?

Yes, and that is the solution the USDA offers when an existing chip works but is not ISO-compliant: have your vet implant a second, compliant chip. Both numbers must then appear on the dog’s health certificate.

Does the rabies vaccination have to be redone if the chip came later?

Yes. The CDC says a rabies vaccine given before the microchip was inserted is invalid, and the British government warns the pet will need to be vaccinated again. The waiting period that follows the vaccination then starts over.