The ISO Microchip: Why Your Pet's Chip Might Not Be Accepted Abroad

What Is an ISO Microchip?

An ISO microchip conforms to ISO standards 11784 and 11785. These standards specify a 15-digit identification code and ensure that the chip can be read by standard scanners used at borders and veterinary checkpoints worldwide. The chip is about the size of a grain of rice and is implanted under the skin between the shoulder blades.

Why Might Your Pet's Chip Be Rejected?

Older microchips - particularly those implanted before international standards were widely adopted - may use a 9 or 10-digit code and a different frequency. These non-ISO chips cannot be read by standard international scanners.

If a border official cannot read your pet's chip, your pet may be refused entry or placed in quarantine, even if all your other documents are in order.

🌍 The US Exception

The United States historically used a different microchip standard (FDXB vs FDXA). While the US has moved towards ISO compliance, some US-chipped pets still have non-standard chips. If your pet was microchipped in the US, it is worth asking your vet to verify the chip standard before international travel.

⚠️ Microchip Before Vaccination - Always

This is a critical sequencing rule: the microchip must be implanted before the rabies vaccination is administered. If the vaccination is given first and the microchip implanted second, the vaccination does not count for international travel purposes and you must start the vaccination process again. Pet Holiday Club's timeline tool makes sure you always follow the correct sequence.

How to Check Your Pet's Microchip Standard

Ask your vet to scan your pet's microchip and confirm it is ISO 11784/11785 compliant. You can also check the chip number - a 15-digit number indicates ISO compliance.

If your pet has a non-compliant chip, a new ISO chip can be implanted alongside it (removing chips is generally not recommended).

🎯 Key Takeaway

The microchip is the foundation of international pet identification. Make sure yours meets the international standard before you do anything else. Pet Holiday Club's checklist flags microchip compliance as the very first step for every destination.