Why does my routine tag not work for a guest?

Where the meaning lives

When you configure an automation to recognise a tag, the rule is stored on your phone. The tag is only an identifier.

Another phone reading that identifier has no rule for it, so nothing happens. Correctly.

This is the same reason a routine does not survive a new phone: the meaning was never on the tag.

It is also why an address written to the tag behaves completely differently, since an address means the same thing to any phone.

The tag is identical

Two tags configured the two ways look and read the same. There is no visible difference and no way to tell by looking.

So a household diagnosing this concludes the other phone is faulty, or the tag is unreliable, and both are wrong.

Reading the tag settles it in seconds: if it holds an address, anyone can use it, and if it holds nothing meaningful, the routine is personal.

That single check saves an argument.

Making it work for others

Write an address that acts, on a domain you control, so any phone tapping it reaches something that does the work.

Or configure the same routine on each phone that needs it, which works and has to be repeated for every phone and every change.

Or move the action into a system rather than a phone, where a home scene is available, since the system serves everyone.

The address route is the only one that works for a guest who has installed nothing, which is usually the case that matters.

What still will not work

Anything that changes settings on the guest's phone, since that requires configuration on their device by definition.

Anything requiring your accounts, which they do not have.

And anything on a phone that is asleep or does not read tags at all, which no design overcomes.

So the honest scope is that a shared tag can trigger something in the world, and cannot change something on somebody else's phone. That boundary is worth knowing before promising a guest anything.