People ask this question with real worry in their voice, and the worry is misplaced but the instinct behind it is good.
Here is what is physically on the card: a short web address. That is the entire contents. There is no name, no phone number, no email, no photograph, no contact file, no encrypted blob waiting to be cracked. The chip holds a link, the phone opens the link, and the browser does the rest.
So when you lose one, the person who picks it up can visit your public profile. The same public profile you have spent the week deliberately showing to strangers.
Why this is less alarming than it sounds
A business card is a public document. Its entire purpose is to be given to people you have just met, some of whom you will never see again, several of whom will leave it in a taxi. Paper cards have been getting lost for a hundred and fifty years and the profession survived.
A tap card is the same category of object with one difference in your favour. When a paper card goes missing, the information on it is frozen and out of your control forever. When a tap card goes missing, you can change what it points at.
That is worth sitting with for a second. If you leave a company, the paper cards in circulation still show your old title and a phone number that now belongs to somebody else. The tap card can be updated in a minute.
What losing it is not
It is not like losing a phone. There is no account access. Nobody can read your email, see your messages, open your banking app or find a saved password, because none of that is reachable from a link. There is nothing to unlock.
It is not like losing a key card either. It does not open a door, authorise a payment or identify you to a system. It resolves to a web page and stops.
The part that is actually your job
The card is not the thing to control. The profile is.
Whatever is on your profile is visible to every person you tap, every person they forward it to, and anyone who finds the card on the floor of a conference centre. That is not a flaw, it is the point. But it means the decision about what goes on there deserves five minutes of thought rather than none.
The test is simple and it has not changed since paper. Would you print this and hand it to a room full of people you do not know? Your work email, yes. Your company address, yes. Your personal mobile, maybe, and that is a real choice rather than an obvious one. Your home address, no.
Most people put too much on, once, and then trim it. The advantage you have is that trimming it takes a minute and works retroactively, including on the card somebody lost last March.
If you do lose one
Order another. Move the profile to the new card. The old one, wherever it is, now points at whatever you want it to point at, or at nothing.
That is the whole recovery procedure, and the fact that it is this short is the actual answer to the question.