Pet Microchip Scanners in the UK: How They Work and Why They Matter
Microchipping is a legal requirement for dogs in the UK, but how does the scanning process actually work? Understanding microchip technology — and its limitations — helps you ensure your pet can always be identified and returned to you if they go missing.
Key takeaways
- A microchip is only useful if the contact details on the linked database are current — update your records every time you move or change number.
- Cats in England must be microchipped by law from June 2024 — the same standard applies as for dogs.
- Use Microchip Central or CheckAChip.co.uk to check whether a found animal's chip is registered across multiple UK databases.
How Pet Microchips and Scanners Work
A pet microchip is a passive RFID (Radio Frequency Identification) device, roughly the size of a grain of rice. It contains no battery and produces no signal on its own. When a scanner emits a radio frequency signal close to the chip, the chip is activated and transmits its unique 15-digit ISO code back to the scanner.
The code itself contains no personal information — it's simply a number that links to a record on a microchip database (such as Petlog, Microchip Central or PETtrac) where the owner's contact details are stored. This means keeping your database record up to date is just as important as the chip itself.
The vast majority of UK microchips operate at 134.2kHz using the ISO 11784/11785 standard. Universal scanners can read chips across all frequencies and are standard in UK vet practices, rescue centres and local authorities.
Who Carries Microchip Scanners in the UK?
All UK vet practices are equipped with microchip scanners — scanning a found animal is one of the first steps any vet will take. The RSPCA, Dogs Trust, Battersea, Blue Cross and virtually all rescue centres also use scanners routinely.
Local authorities (councils) that provide a stray dog collection service are required by law to scan and check for a microchip. Police forces also use scanners when animals are seized or found following incidents.
Most Pets at Home stores have scanners available for free use. If you've adopted a pet and aren't certain it has a working chip, a free scan at a vet or pet store will confirm this within seconds.
Common Microchipping Problems in the UK
Chip migration is the most common technical issue — chips can move from the original implant site (between the shoulder blades) to elsewhere in the body. A thorough scan of the whole animal should identify a migrated chip. Always inform the scanner operator if you suspect migration.
Chip failure, though rare, does occur. Older chips and certain brands have higher failure rates. If your vet cannot detect a chip, a replacement can be implanted, typically costing £31–£40. Some insurers will cover re-chipping costs.
Database errors are arguably the bigger problem. A chip that's not registered, registered on a database that isn't searched, or registered with outdated contact details is functionally useless. In the UK there are multiple competing microchip databases, which creates fragmentation — Microchip Central was launched to address this by searching across databases simultaneously.
The UK Microchip Database Landscape
The UK has several approved microchip databases, including Petlog (run by the Kennel Club), PETtrac (run by AVID), MicrofinderCIS, IdentiBase and others. Microchip Central and CheckAChip.co.uk are lookup tools that search across multiple databases simultaneously — these are the most useful tools for found animals.
From 10 June 2024, cats in England are also required by law to be microchipped before the age of 20 weeks. This significantly increases the number of chipped animals in the UK and puts greater pressure on database accuracy.
Whenever you move house, change phone number or email address, update your details on every database where your pet is registered — not just one. This is a legal obligation for dog owners and a strong practical recommendation for all pet owners.
Home Microchip Scanners: Are They Worth It?
Consumer-grade microchip scanners are available online for around £30–£100. They allow owners to confirm their pet's chip is working and readable without a vet visit. This can be useful for breeders, rescue fosterers or owners with multiple animals.
However, for most pet owners, there's little need to own a scanner. Free scanning is available at most UK vet practices and Pets at Home stores. Consumer scanners may not read all chip frequencies, so a universal scanner at a vet is always the most reliable option.
If you've recently adopted a pet whose history is unclear, asking your vet to scan on your next visit is the simplest approach. They can also check which database the chip is registered on and advise on updating records if needed.
Find a Vet Near You
If your pet needs microchipping or you want to check whether their existing chip is working and correctly registered, a vet can help. Use CompareMyVet at app.comparemyvet.uk to find and compare local vet practices and microchipping costs near you.
Common questions
The procedure involves a needle slightly larger than a standard injection and is comparable in sensation. Most pets show no more reaction than they would to a vaccination. It can be done during a routine vet visit without sedation.
An unregistered chip means the scanner can read the number but it links to no record, making it impossible to trace the owner. If you're unsure whether your chip is registered, visit gov.uk to check using the official microchip checking service.
No. Standard microchips are passive RFID devices with no GPS capability and no power source. They cannot transmit a location signal. For real-time location tracking, a separate GPS tracker device is needed.
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