How to prove a lost pet is yours (UK)

• A microchip registered to you on an approved database. It's one of the things the police or a court will look at, but Petlog, the Royal Kennel Club's database, says registration reflects keepership, not legal ownership.
• Vet records in your name for that animal, including vaccination history and any treatment.
• Purchase or adoption paperwork, or a receipt from a breeder or rescue.
• Insurance documents naming the pet.
• Dated photographs of you with the pet, especially ones showing distinctive markings.
• A pet passport or animal health certificate if they have travelled.

No single item is a legal trump card, but a microchip in your name plus vet records in the same name is rarely argued with. The weakest position is a pet bought privately for cash, never registered and never seen by a vet.

A microchip only proves ownership if the database entry is yours. Chips still registered to the breeder, the rescue or a previous owner are extremely common, because the transfer is a separate step people forget. If your pet went missing today, the database might name somebody else.

Check yours now — it is free and takes five minutes. Our guide to updating microchip details walks through it, and every approved UK database lists who to contact if you don't know which one holds the record.

The databases stay neutral in a dispute. Petlog says it can't decide who legally owns a pet. It will only mark a record as disputed when there's an active court case, and it needs court papers or a police crime reference number before it will refuse a request to transfer the pet to someone else. Without those, it processes transfers as normal.

So if your pet is missing or you think it's been taken, tell the database straight away so a marker goes on the record, and if you've left your pet with someone temporarily, such as a friend or a foster carer, keep it in writing. In a real dispute, Petlog's advice is to get independent legal advice.

1. Stay calm and polite. The person may genuinely believe they rescued a stray, and an argument can make them dig in.
2. Offer evidence rather than demanding the pet: the chip number, the database, your vet's name. Ask them to have the chip scanned at any vet — it is free, takes a minute and settles it.
3. For a dog, report it to your local council's dog warden. Councils have legal duties over stray dogs, and a found dog is supposed to be reported to them. Ask them to contact the finder.
4. Report it to the police, especially if you believe the pet was taken rather than found. Ask for a crime reference number. A pet is property under the Theft Act 1968, and keeping property you know belongs to somebody else can be theft.
5. Keep everything in writing after the first conversation — messages, times, what was said. If it ends up as a civil claim, the paper trail is what matters.

Cats are treated differently from dogs in practice: there is no cat warden and no equivalent duty on councils, so the microchip and the vet are your main route.

For dogs, the council route matters. A stray dog reported to the council and unclaimed can be rehomed after seven clear days, which is why reporting your dog missing to the council early is not a formality. Our dog warden guide sets out the timeline.

A finder who keeps a dog without reporting it is not following the law, but the practical answer is still the microchip and the warden, not an argument on a doorstep.

• Register the chip in your own name, and check it once a year.
• Keep one folder — paper or phone — with the chip number, the database, the vet's details and the adoption or purchase receipt.
• Take a clear photo of your pet every few months, including any unusual markings, and one of the two of you together.
• Put a tag on the collar that identifies the pet as owned, not stray. That alone stops most well-meaning people deciding a wandering cat has no home.

A QR code pet tag helps here in a way an engraved tag can't: whoever scans it sees your pet's profile, the photo you chose and a note in your own words, which is immediate, visible evidence that the animal is somebody's pet — and with lost mode on, you're emailed the moment it's scanned.