Can a tag identify a pet or a piece of luggage?
It can, and it depends entirely on a finder thinking to tap it. A printed phone number reaches everybody including people with no NFC, so the tag is the supplement and the print is the plan. That order is the whole answer.
The finder problem
Somebody finds a dog or a suitcase. For a tag to help, they must notice it, recognise what it is, own a phone that reads tags, and think to try.
Each of those is a filter, and together they remove most finders.
A printed phone number removes all four filters at once. It is read by anyone, including someone with no phone at all who can pass it to somebody else.
So the design question is not whether a tag works. It is what happens for the finders it does not reach.
Print is the primary
A visible printed number, or a printed address short enough to type, on the outside of the object.
Large enough to read without effort, since the person reading it is holding a struggling animal or standing in an airport.
On luggage, printed inside as well as outside, because outside tags are torn off in transit more often than anything else.
And keep it current, which sounds obvious and is the commonest failure of every lost property system ever devised.
What the tag adds
Depth without clutter. A page can carry the vet, the medication, the microchip number, a photograph, and a message, none of which fits on a collar.
Changeability, since a page can be updated when you travel, when a number changes, or when the animal needs different care.
And the ability to say something to the finder that a bare number cannot, which is genuinely useful when somebody is deciding whether to get involved.
Range is the practical limit: a collar tag is small, so the finder must hold a phone against it deliberately.
Not the same as a microchip
A pet microchip is a different technology at a different frequency, read by veterinary scanners rather than by phones.
It is the identification that matters legally and to a vet, and a collar tag does not replace it.
A collar tag is for the member of the public who finds the animal before a vet is involved, which is a different and useful job.
Have both, and put the microchip number on the page behind the tag so a finder can pass it on.
Frequently asked questions
Is a tag better than a printed number?
No. Print reaches everybody, and the tag adds depth for the finders who can use it. Print is the plan and the tag is the supplement.
Does it replace a pet microchip?
No. A microchip is a different technology read by veterinary scanners, and it is the identification that counts legally.
Will an airline tag survive?
Outside tags are torn off routinely, which is why the same details should be printed inside the case as well.
What should the page say?
Enough for a finder to act: how to reach you, anything urgent about the animal, and the microchip number to pass on.