Quick answer: A microchip is a tiny chip about the size of a grain of rice, placed under your dog's skin between the shoulder blades. It is not a GPS tracker. When a shelter or vet scans it, they see a number that links to your contact details in a registry, so it only works if you register it and keep your phone number and address up to date. Pair it with a well fitted collar and an ID tag showing your phone number. Check both every new year and before holidays, moves and travel.

Why does my dog need ID?

Any dog can get lost. A gate left open, a doorbell, a loud bang or a squirrel can send even the best trained dog running. Lost dogs can travel surprisingly far, and many end up at shelters, vet clinics or in a neighbor's yard. Without ID, finding their family can take a long time or may not happen at all.

ID makes reunions much more likely. Studies of shelter dogs in the US have found that microchipped dogs were returned to their owners far more often than dogs without chips, roughly half compared with around one in five in one large study. Many chipped dogs that were not returned had chips that were never registered or had out of date details.

Some times of year are riskier. Fireworks on New Year's Eve and the Fourth of July, holiday parties with open doors, travel, house moves and storms all lead to more lost dogs. Our New Year's Eve fireworks guide explains how to keep your dog safe on the noisiest night of winter.

Many areas require ID. Many cities and counties require dogs to wear a license tag, and some require rabies tags too. Some places and countries also require microchips. Check your local rules, especially if you have moved recently.

How do dog microchips work?

A microchip is a tiny electronic chip, about the size of a grain of rice, sealed in a safe glass or polymer capsule. It has no battery and no moving parts. Each chip holds a unique identification number. It is designed to last for your dog's lifetime.

It is not a GPS tracker. A microchip cannot show where your dog is. It only works when someone finds your dog and scans it with a microchip scanner. Shelters, animal control and most vet clinics have scanners and check every stray animal that comes in.

The scanner reads the number, and the number is looked up in a microchip registry database. If you have registered the chip and kept your details current, the registry or the person who scanned the chip can contact you. If the chip is not registered, the number leads nowhere.

Most chips follow an international standard. Many modern chips are 15 digit ISO chips that most scanners can read. Older or non standard chips may need a universal scanner. If you plan to travel abroad with your dog, check the microchip requirements for your destination well ahead of time.

How is a microchip put in, and does it hurt?

A microchip is placed with a needle, usually under the skin between the shoulder blades. It is similar to a routine vaccine injection, though the needle is a little larger. Most dogs react about the same as they do to a vaccine, and no anesthesia is needed.

Many dogs are chipped during spay or neuter surgery, when they are already asleep. Shelters and rescues often microchip dogs before adoption, so check your adoption paperwork. Breeders may chip puppies before they go home.

Problems are rare. Microchips are very safe. Rarely, a chip can move from where it was placed, stop working or cause a small lump at the site. Your vet can scan your dog at each checkup to make sure the chip is still readable and in place.

Microchipping is affordable. Costs vary by area, but microchipping often costs about $25 to $75 at a vet clinic, and many shelters and low cost clinics offer it for less. Some registries charge a small fee for registration or extra services, while many basic registrations are free. Our dog cost guide covers other first year expenses.

Why is microchip registration so important?

Registration is the step most people miss. A microchip is only as useful as the information linked to it. If the chip is not registered, or if your phone number or address has changed, a shelter that finds your dog may not be able to reach you.

Check who your chip is registered with. Your vet, shelter or breeder should give you the chip number and registry name. If you do not know it, ask your vet to scan your dog and look up the chip number. The AAHA Universal Pet Microchip Lookup tool can show which registry a chip is linked to.

Register in your own name. If your dog was chipped by a shelter, rescue or breeder, the chip may still be registered to them. Transfer it into your name with your current phone number, email and address. Add a backup contact, like a family member or friend.

Keep details up to date. Update the registry every time you move, change phone numbers or change email. Set a reminder to check your details every new year. It only takes a few minutes and can make the difference between a quick reunion and a long search.

What should I put on my dog's ID tag?

Your phone number is the most important line. Put your mobile number first and make it large and easy to read. A second number for a partner or family member is helpful. Anyone who finds your dog can read a tag instantly, without a scanner, so tags often lead to the fastest reunions.

Add useful extras if there is space. Many owners add their dog's name, their town or street, the word microchipped and any medical needs, like needs medication or deaf. Some people prefer not to put their dog's name on the tag for security reasons. Choose what feels right for you.

Keep it clear and durable. Choose a tag made from strong metal with deep engraving, and replace it when the text wears down. Silent tags, slide on tags and tags riveted to the collar avoid jingling and are less likely to fall off. Check that the tag ring is secure.

Add license and rabies tags if required. Many areas require dogs to wear a license tag and a rabies vaccination tag. These tags link to records that can help identify your dog. Keep them on the collar along with your ID tag.

How should my dog's collar fit?

Use the two finger rule. You should be able to fit two fingers comfortably between your dog's collar and its neck. Too loose and it can slip over the head. Too tight and it can rub or cause discomfort. Check fit often for growing puppies and after weight changes.

Choose the right collar for your dog. A sturdy flat buckle or clip collar works for most dogs. Dogs with narrow heads, like Greyhounds and Whippets, may need a martingale collar so they cannot back out of it. Breakaway collars release under pressure, which can prevent snagging, but they may come off if your dog runs.

Wear ID even at home. Many dogs get lost from home, often through open doors or gates. Keeping a well fitted dog collar with an ID tag on your dog at all times, except during crating if your vet or trainer advises, gives the best protection.

Check collars and clips regularly. Look for fraying, worn holes, weak buckles and loose rings. Replace worn collars and leashes promptly. A bright, comfortable collar also makes your dog easier to see on dark winter walks.

What other ID options are there?

GPS and smart trackers clip onto the collar and can show your dog's location on a phone app. They are helpful for dogs that tend to escape or that hike off leash. They need charging, may require a subscription and can fall off, so use them alongside, not instead of, a microchip and ID tag.

Embroidered or engraved collars print your phone number directly on the collar. They cannot fall off like a tag and do not jingle. Many owners use one as a backup to a regular tag.

Up to date photos are essential. Keep several clear, recent photos of your dog on your phone, including a close up of its face, a full body side view and any unique markings. Good photos make lost dog posters and social media posts much more effective.

Keep records together. Store your dog's microchip number, registry details, vaccine records, license number and vet details in one place on your phone and in a paper file. In an emergency, having everything ready saves precious time.

How do I check my dog's microchip and ID?

Ask your vet to scan the chip at every annual checkup. This makes sure it is still working and readable. Your vet can also confirm the chip number on your dog's record matches your paperwork.

Look up your registration online. Use the chip number to check your registry account. Confirm your name, phone numbers, email and address. Add or update backup contacts. Some registries let you upload a photo of your dog, which can help with reunions.

Inspect the tag and collar. Make sure the engraving is clear, the phone number is current and the tag is firmly attached. Check the collar for wear and fit. Replace anything that looks tired.

Make it a yearly habit. A good time to check is every new year, before holiday travel and after any move or phone change. Our New Year's resolutions guide includes an ID check as an easy win for the year ahead.

What should I do if my dog goes missing?

Search right away. Check your home, yard and neighborhood, calling your dog's name in a calm, happy voice. Bring treats and a squeaky toy. Ask neighbors to check sheds, garages and yards. Many lost dogs hide close to home, especially if they were scared by noise.

Report your dog as missing. Contact your microchip registry to mark your dog as lost and confirm your details. Call local shelters, animal control and vet clinics, and visit shelters in person if you can. Give them your dog's description, photos and microchip number.

Spread the word. Post on local lost pet groups, neighborhood apps and social media with clear photos and the area where your dog went missing. Put up flyers with a large photo and your phone number. Ask local businesses to display them.

Do not chase if you see your dog. Running toward a scared dog often makes it run further. Crouch down, turn sideways, speak softly and toss treats. Leave a familiar item with your scent, like a worn shirt or your dog's blanket, outside your home.

What should I do if I find a lost dog?

Approach calmly and carefully. A scared dog may run or bite. Move slowly, crouch down, avoid staring and let the dog come to you. Offer a treat if you have one. If the dog seems aggressive or very frightened, keep your distance and call animal control.

Check for an ID tag. If the dog has a tag, call the number right away. Many reunions happen within minutes this way. Look for license or rabies tags too, which can link to the owner through local records.

Get the dog scanned for a microchip. Take the dog to a nearby vet clinic, shelter or animal control office to be scanned. This is free in most places. If a chip is found, the registry can contact the owner.

Report the found dog. Contact local shelters and animal control, and post on local lost and found pet groups with a photo. Follow local laws about found animals. Keep the dog safe and separate from your own pets until the owner is found or the dog is taken to a shelter.

• A microchip is permanent ID, but it is not a GPS tracker.
• A chip only works if it is registered with your current details.
• ID tags give the fastest reunions, because anyone can read them.
• Put your phone number first on your dog's ID tag.
• Check chip and tag details every new year and after any move.

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How does a dog microchip work?

A microchip is a tiny chip under your dog's skin with a unique number. When a vet or shelter scans it, they see the number and look it up in a registry to find your contact details. It only works if the chip is registered with current information.

Can a microchip track my dog's location?

No. A microchip is not a GPS tracker. It cannot show where your dog is. It only helps identify your dog when someone finds it and scans the chip. GPS collar trackers are a separate option.

Does microchipping hurt dogs?

Most dogs react about the same as they do to a routine vaccine. The chip is placed with a needle under the skin between the shoulder blades, and no anesthesia is needed. Many dogs are chipped during spay or neuter surgery.

How do I find out who my dog's microchip is registered with?

Ask your vet to scan your dog for the chip number. Then use the AAHA Universal Pet Microchip Lookup tool to see which registry it is linked to. Contact that registry to check or update your details.

How do I update my dog's microchip information?

Log in to your microchip registry account, or contact the registry by phone, and update your phone numbers, email and address. Add a backup contact. Do this every time you move or change numbers.

What should I put on my dog's ID tag?

Your mobile phone number is most important. Add a second number if you can. Many owners also add their town, the word microchipped and any medical needs. Whether to include your dog's name is your choice.

Does my dog need an ID tag if it has a microchip?

Yes. Anyone can read an ID tag instantly, without a scanner, so tags often lead to the fastest reunions. A microchip is a permanent backup in case the collar comes off.

How much does it cost to microchip a dog?

Microchipping often costs about $25 to $75 at a vet clinic, with lower prices at many shelters and low cost clinics. Many registries offer free basic registration, while some charge for extra services.

Can a microchip stop working?

It is rare, but chips can occasionally fail or move. Ask your vet to scan your dog at each annual checkup to make sure the chip is still readable and in place.

Should my dog wear a collar at home?

For most dogs, yes. Many dogs get lost from home through open doors and gates. A well fitted collar with an ID tag gives the best protection. Some trainers advise removing collars during crate time to avoid snagging.