How do you update your details after handing out cards?
Only if the card holds an address you control. Change what that address resolves to and every card ever handed out is updated at once. Cards holding your details directly are frozen, and the ones already in other people's wallets cannot be recalled.
The asymmetry that decides it
A card holding a link can be updated by changing the page. A card holding your details cannot be updated at all once it has left your hands.
That is not a small difference in convenience. It is the difference between a correctable mistake and a permanent one, distributed across everyone you have met.
And you find out which you have at the worst moment: when something has already changed.
Own the address
The link only helps if you control where it points. An address on a domain you own can be redirected forever.
An address on a third party platform belongs to that platform. If the service closes, changes its terms or you simply want to leave, every card you handed out points somewhere you no longer control, and there is no way to reach those cards.
This is the single most consequential decision in an NFC card deployment, and it is invisible at purchase time because both options look identical on the card.
Using your own domain costs very little and removes the dependency entirely. The page behind it can still be built on any platform you like.
If the cards are already frozen
Cards holding contact details directly, and still in your possession, can be rewritten unless they were locked.
Cards already handed out cannot. What you can do is make sure the details still work: keep an old number forwarding, keep an old address receiving, and accept that the card will age.
Where the cards point at a platform you are leaving, ask whether the provider will redirect. Some will and it is not something to rely on.
And treat the next run differently. The cost of reprinting is small against the cost of a second frozen batch.
What changes more often than you expect
A phone number, when a company changes system or a person changes role.
A job title, which changes more often than anything else on a card.
An email address, when a domain changes after a merger or a rebrand.
And the company itself. People change employers, and a card that survives the change is a card whose link you personally control rather than one your employer does. Which of those you want is a real decision, and it is worth making deliberately rather than discovering later.
Frequently asked questions
Can I update a card someone already has?
Only through the address it holds. Change what the address resolves to, and every card ever handed out follows.
What if my cards use a provider's domain?
Then the provider controls where they lead. Moving to your own domain is worth doing before the next print run rather than after.
Can I rewrite cards I still have?
Yes, unless they were locked. Locking is permanent, so check before assuming a card can be corrected.
What happens if I change employer?
A card pointing at a company controlled address stops being yours. If that matters, use an address you own personally.