How to choose a pet ID tag: what actually matters

Engraving on soft metals like brass and plated tags wears smooth faster than on hard ones like stainless steel. Plastic tags are quiet and light, so look for a thick one with the details printed in rather than on the surface. Whatever you pick, the test is whether a stranger can read it at arm's length after a winter of mud — see why dog tags go blank.

• A hanging tag on a split ring is the standard, and the ring is the weak point. Check it monthly and replace it when the spiral gapes. Our guide to attaching a tag to a collar shows how to fit one securely.
• A slide-on tag threads onto the collar strap. Nothing dangles, nothing jingles, and there is no ring to open — but it needs to match your collar's width.
• Attach to a separate ring rather than the D-ring the lead clips to, so lead pressure doesn't work the ID loose.

For dogs in the UK this is not a matter of taste. The Control of Dogs Order 1992 requires the owner's name and address on the collar or on a plate or badge attached to it, and your house number or name plus your postcode is the shortest way to fit the address. A phone number is optional, but it's the quickest way for a finder to reach you.

What you leave off is your choice. The law doesn't ask for your pet's name, and some owners leave it off, because a stranger who can call a dog by name finds it easier to coax them away. Our guides on what to put on a dog tag and what to put on a cat tag go through the options.

Engraved tags are fixed. Move house, change your number, or need to say the dog is on medication, and you buy another tag — and in the gap, the tag is wrong, which is worse than blank.

This is the real argument for a scannable tag. A QR code pet tag points at a profile you edit from your phone, so the number is always current, and you can add a photo, medical notes and a line about how they behave when frightened — none of which fits on a disc the size of a 10p piece. For dogs, see the best QR dog tags compared, and if you're tempted to make your own, read that first.

• Dogs: strength and readability matter most, and the legal name-and-address requirement applies.
• Cats: weight and snagging matter most. A light, flat tag on a quick-release collar, with no dangling bulk. There is no legal tag requirement for cats, but in England a pet cat must be microchipped by the time it's 20 weeks old.
• For cats, also think about the bell question — the research and the risks are in should a cat's collar have a bell.

Two pieces of ID, not one. A microchip as the backstop that works at a vet or a rescue, and a tag as the thing that works in the hands of whoever actually finds your pet in the street. For a dog, that often means two tags: an engraved one carrying the legal name and address, and a scannable one carrying everything else.

If you want the reasoning rather than the recommendation, QR pet tag vs microchip vs GPS tracker compares what each one can and cannot do, including where trackers with monthly fees genuinely earn their keep.