If you own a dog or a cat in the UK, they should be implanted with a microchip which helps identify them as yours by the database data linked to it. Over the last 10 years this has become compulsory by law after campaigns from animal welfare charities and vets. What exactly is a microchip and why do those who work with animals think they are so important? This article will look at just that.
Summary
A microchip is a small computer chip implanted under your pets skin with a unique number that can be scanned
Microchip details are stored securely on multiple databases in the UK, and can be accessed by vets, rescue centres, councils and the police
It is a legal requirement that all dogs over 8 weeks old in the UK and all cats over 20 weeks old in England have a chip registered with up-to-date details
You can be fined up to £500 if you do not meet these legal requirements
Microchips can have many other uses by helping to uniquely identify your pet
What is a microchip?
A microchip is a tiny glass computer chip (around the size of a grain of rice) that is inserted under the skin of an animal. When scanned, this brings up a unique number that links to your details on a database. It is the only way we have to uniquely and officially identify individual animals, and it can be done on a whole range of species. In the UK, it is a legal requirement for pet dogs and cats to be microchipped and their details kept up to date.
How is a microchip inserted?
A microchip is inserted using a special needle applicator into the scruff, the area of loose skin around the back of the neck. This is the same way a vet would give a vaccination, and the microchip sits harmlessly in the fat layer above the muscle but under the skin.
Microchips can easily and painlessly be inserted in conscious animals, and they do not usually need sedation and anaesthesia.
Does a vet have to microchip my pet?
Microchips have to be inserted by trained professionals, and vets are the most usual of these. They can also be inserted by Registered Veterinary Nurses and trained staff from rescue centres and local councils. Do not have your pet microchipped by someone who is not in one of these professions as it could lead to a faulty chip or damage to your pet.
How does a microchip help keep my pet safe?
A microchip helps keep your pet safe by identifying them as yours. If your pet were to get lost or have an accident, they will hopefully be taken to a vet, rescue centre, dog warden or the police. Any of these places will have microchip scanners which can pick up the 15 digit number on the chip, and so can then search databases to see who the pet belongs too. They can then get in touch with you to reunite you with your pet, or to let you know what has happened to them.
Can’t I just use a collar and tag?
It is a legal requirement for a dog to have a collar and tag (but not a cat) but this is not enough on its own for your pet, either legally or practically. Collars can be easily lost (or changed), and are not unique to your pet, especially if the tag goes missing. Collars can in themselves be a health hazard; cats in particular can have real issues with collars getting stuck around their front legs, or can even hang themselves from trees and fences on them. Safety collars are always advised for cats but this can get very expensive when they do what they are meant to do and snap off your cat’s neck if they get stuck!
There are now many other ways of tracking your pet (such as airtags, smart collars and QR codes) which can be useful to you as an owner, but are not helpful to vets, dog wardens or police when they find your pet.
What are the laws about microchipping?
Microchipping your pet has been a legal requirement in the UK for dogs since April 2016, and for cats in England since June 2024. You can be fined up to £500 if your dog or cat is not microchipped when they should be.
Microchipping laws for dogs
All dogs in the UK must be microchipped and registered on a recognised database by the time they are 8 weeks old. In practice, a puppy should be microchipped and registered by the breeder before going to their new home, as it is not advised to separate puppies from their mothers before 8 weeks old.
Microchipping laws for cats
Owned cats in England must be microchipped before reaching 20 weeks of age (including cats that will never go outdoors) and their details kept up to date on a recognised pet microchipping database. It is advised (but not yet law) to follow these guidelines in Wales, Scotland and Northern Ireland.
Exemptions to microchipping laws
It is not a legal requirement to microchip cats who live with little or no human interaction, such as farm, feral or community cats.
There are no exemptions for dogs in the UK – all dogs over 8 weeks old must be microchipped.
My pet microchipped outside the UK, what should I do?
If your pet was microchipped outside the UK and imported, the chip must comply with ISO standards (ISO11784/11785) and be registered on a UK compliant database. UK databases will register chips implanted abroad.
Chips implanted outside the UK are sometimes in different places, such as on the bottom of the neck. Make sure you know where your pets chip is, and if necessary get a second one in the scruff so it is not missed.
Other useful things a microchip can do
Microchips can have other uses as well as just providing your details when scanned.
If your pet gets lost or stolen
If your pet goes missing and you are worried they are lost or stolen, you can contact the chip database to have an alert put on their account. This means that if your pet is taken to a vet, dog warden, rescue centre or police station that their account is flagged, and the professional will be aware of the situation and can act accordingly.
Flaps and food bowls
Microchip technology means it is possible to have door flaps that only open for the pet they are meant to. This is an excellent way of ensuring wild or strange animals do not get into your house, and you can even programme them to ensure your pet is inside or outside when you want them to be.
There are also food bowls with lids and microchip scanners that mean only the intended pet can eat the food inside them – perfect for multi-pet households when one is on a special diet.
Pet travel and showing
If you ever want to travel with your pet or take them to shows, their microchip is the only thing that is allowed to be used to identify them.
Can microchips cause any problems for my pet?
Microchips themselves are not harmful for your pet, and they are not associated with any long term side effects. They might cause a small amount of tenderness around the time of insertion, but this quickly passes. If the insertion site is rubbed on the day of chipping it is sometimes possible for the microchip to fall out, so it’s important to leave the area alone so the skin can heal.
A very small percentage of chips can stop working over time, and because microchips sit in the fat layer, they can sometimes move about! When you go to the vet it’s always worth asking them to check for the chip to make sure where it is and that it is still working.
Where are my details stored and are they safe?
Your details should be stored on one of the 24 compliant databases listed on the gov.uk website. This ensures that your details are held securely under GDPR and that the correct details are included.
It is a common misconception that there is one national database for all pet chips and that vets are able to change details for you – whilst this is true in other countries and seems sensible, it is not the case in the UK!
What most people miss – keep your microchip details up to date!
A microchip is of absolutely no use to anyone if the details on them are not kept up to date, and it is your legal responsibility as your pet’s owner to ensure that they are. You are the person who has to contact the chip database to change any details, and there may sometimes be a small fee for this.
There are two key times that can catch people out:
When the chip is implanted
Sometimes the place that chips your pet will register your details for you, sometimes they won’t – make sure you check what has been done already and what you have to do next. Most vet practices can register your pet through their practice management system, but you still need to create your own account with the database to fully complete the process. You should end up with emails and/or paperwork to keep, which confirm which database your chip is registered to and how to access it.
If your details change
Life happens, and we move house, change emails or get a new SIM card. It may not be the first thing on your mind but it is essential that you contact your chip database to ensure they update your details to the new ones. Fail to do this and someone may have your lost pet but be unable to get them back to you as all they have is your name, but no address or phone number.
Do microchips have anything to do with insurance?
Insurance policies will require your pet to be compliant with current advice around microchipping and vaccination, and many will ask for your pet’s chip number before you can take out a policy. Make sure you check the small print to see what your policy requires.
How much does microchipping cost?
Microchipping typically costs between £10-£30 with the average cost around £15-£25.
Breeders and rescue centres often incorporate this cost into their sale and adoption fees, and most vet practices will offer this as part of a puppy or kitten package, or at a reduced price as part of a pet health plan.
A vet’s take on microchipping
“As a vet I have considered microchipping as essential long before the law changed in 2016 and 2024. Lost pets are frequently brought into us in practice, and an up-to-date microchip can mean the difference between a successful reuniting of pet with owner (my record was contacting the owner before they had even realised the dog had broken out of the garden!), or having to send an animal to the dog warden or to a rescue centre. In the horrible situation of an animal being brought in dead after a car accident, the presence of a microchip can help bring much needed closure to worried owners.
I’d always recommend asking your vets to check the chip each time you go in to make sure it’s still working, and please please please remember to update your details when they change!”
Dr Siân Burwood MA VetMB MRCVS
References
Microchipping Cats | What You Need to Know | Cats Protection
Dog Microchipping Questions & Answers | Dog Advice | Dogs Trust
Get your dog or cat microchipped - GOV.UK