How do you update a Wi-Fi tag after a password change?
By rewriting every tag by hand, which is the one situation on this site where pointing at a page does not save you. Credentials have to be on the tag to work offline, so changing them means visiting each tag physically.
Why the usual trick fails
Almost everywhere else on this site the advice is the same: write an address you control and change what it points at.
A Wi-Fi record cannot work that way. It joins a network because it holds the credentials, and credentials behind a link are not credentials the phone can act on.
So a Wi-Fi record is content rather than a pointer, and content on a tag is frozen until somebody rewrites it.
That is the real cost of the offline capability, and it is worth knowing before you deploy twenty of them.
Rewriting in practice
Find every tag. This is the step people underestimate, particularly in a rental or an office where tags were added over time.
Rewrite each one and read it back to confirm, because a write that did not persist leaves a tag holding the old password.
Check that none of them were locked, since a locked Wi-Fi tag cannot be updated at all and has to be replaced.
And update the printed details beside each tag, which are the version most guests will actually use.
Unless you use a page
A tag holding a web address to a page showing the credentials can be updated centrally, like everything else.
The guest reads the page and types the password, or scans a code the page displays. It is one step more for them and no steps for you.
It also works on every phone rather than on one platform, which is a second reason to prefer it.
The cost is coverage: a guest with no signal cannot reach the page, and a guest asking about your Wi-Fi frequently has no signal.
Planning for the change
Keep a list of where the tags are, written down. It is the difference between an hour and an afternoon.
Never lock a Wi-Fi tag. There is no benefit and it makes a password change into a replacement.
Consider both routes together: a Wi-Fi record for the offline case, and a printed address for everyone else.
And change the password less often, or on a schedule you choose, rather than reactively. The cost of a change is now physical, and that should influence how often you make one.
Frequently asked questions
Can I point a Wi-Fi tag at a page instead?
You can, and the guest then reads the password rather than joining automatically. It updates centrally and works on every phone.
What if the tag was locked?
It cannot be updated and has to be replaced. There is no reason to lock a Wi-Fi tag in the first place.
Do I need to rewrite the printed card too?
Yes, and it is the version most guests use. A tag updated and a card left stale is a confusing combination.
How do I find all my tags?
From a list you wrote when you placed them. Without one, this is a search of the building.