You see more and more of them at trade shows. A matt black card, slightly thicker than an ordinary one. The person holds it to the back of your phone, a notification appears, and their profile opens — with their photo, their mobile number and a button to save it in one tap. It makes a good impression, and an even better one when you are the one handing over the card.
Still, a good impression is not enough to justify buying cards for twelve sales reps. What decides it is knowing what is inside, what exactly happens on contact, and above all in which situations it doesn't work — because those situations exist, no seller is keen to spell them out, and yet they are easy to work around when you know about them in advance.
This article explains how it really works, without the marketing diagrams. We make this kind of card, which makes our conclusions suspect; so we have tried to be precise about the facts, including the ones that don't suit us.
What is really inside the card
A chip a few millimetres across, connected to a spiral copper antenna embedded in the thickness of the card. No battery, no active components, nothing to wear out. They are known by their part number — NTAG213, NTAG215, NTAG216 — and the only practical difference between them is the size of their memory.
That memory is tiny: around 130 usable bytes on an NTAG213, the most common type. And what is written on it fits on one line: a web address. Nothing else. Neither your name, nor your phone number, nor your photo is on the card.
This distinction looks technical. In reality it explains everything else, for better and for worse.
For better: since the card contains only an address, changing your mobile number does not mean reprinting your cards. You edit the page; the cards already handed out keep pointing to the same place and show the new information. That is the central argument for these cards, and it holds up.
For worse: a card that contains only an address depends entirely on what is at the other end. If the page disappears, the card becomes a dead piece of card that nobody can repair, including you. We come back to this below, because it is the real risk with this family of products.
What happens when you hold it to a phone
The phone constantly emits a small magnetic field. Held within a centimetre or two, the card's antenna draws enough energy from it to wake the chip, which returns its address. The phone then displays a notification; you tap it, and the browser opens. The whole thing takes a second.
Compatibility, however, is not uniform — and it is the first thing to check before equipping a team that works with a mixed fleet of phones.
| Reads with no action needed | What it takes | |
|---|---|---|
| iPhone XS and newer | Yes | iOS 14 or later, screen on and unlocked |
| iPhone 7, 8, X | No | Use the "NFC Tag Reader" button in Control Centre |
| iPhone 6s and older | No | Not possible — you need the QR code |
| Recent Android | Yes | NFC switched on in settings |
| Entry-level Android | Varies | Check that the device has an NFC chip: many don't |
One detail accounts for half of all "it doesn't work" cases on its own: the phone's antenna is not in the same place on every brand. On an iPhone, it is at the top of the back, near the lenses. On many Android phones, it is in the middle. A card held to the centre of an iPhone triggers nothing, and people conclude the card is dead when it only needed moving three centimetres higher.
The five cases where it doesn't work
Better to know them before the trade show than in front of a customer.
1. NFC is switched off. This is the most frequent case on Android, where the setting sits in the connection settings and many people have turned it off without knowing. Nothing tells you at the moment of contact: simply nothing happens.
2. The phone is too old. An iPhone older than the XS will not read the card in the background, and an iPhone older than the 7 will not read it at all. At an industrial trade show, where you still come across phones five or six years old, this is not a trivial point.
3. The case blocks it. A thick case is still fine; a metal case, a magnetic plate for a car mount, or an aluminium card holder stuck to the back block the field. Again, no error message.
4. The screen is locked. On an iPhone, background reading only works if the screen is on and unlocked. Holding the card to a phone lying screen-off on a table does nothing.
5. There is no network. This one matters most, and it is the only one no setting can fix. The card delivers an address, not a contact record. You need a connection for the page to open. In an exhibition hall where three thousand people are saturating the same mast, in a basement, in a factory in a dead zone, the phone will read the card perfectly and then sit on a page that keeps spinning.
A QR code does not solve this last point — it too carries nothing more than an address. It does, however, solve the first four, which is why any serious NFC card comes with a QR code, printed on the back or shown on the profile. It is not an admission of weakness: it is the safety net.
An NFC card with no fallback is a card that works for eight people out of ten. On a stand, it is the other two you remember.
What an NFC card doesn't do
It does not capture the other person's contact details. This is the most widespread misunderstanding, and it is costly when you discover after buying that the exchange remains one-way. The card gives your details; it does not capture those of the person you are talking to, exactly like a paper card. To leave with their details, you need another step: scan their card, have them fill in a form, or ask them to message you from your profile. If your problem is coming back from a trade show with forty usable contacts, an NFC card does not solve it — that is a separate subject, which we covered in our comparison of ways to capture a contact on a stand.
It does not install anything. Neither on your phone nor on the other person's. No app is needed on either side; it is an ordinary web page that opens in the browser.
It does not update itself. The page can change, which is the whole point, but someone still has to change it. An NFC card whose profile nobody has corrected in two years shows details just as wrong as an out-of-date paper card — with the added conviction that "it must be up to date because it's online".
It does not tell you who scanned it. A visit counter, yes. The visitor's identity, no: the other person's phone transmits nothing to the card; the communication is one-way. Be wary of a seller who promises you will "know who viewed your profile" — to keep that promise, they would have to put trackers on the page, which is a very different matter as far as the people viewing it are concerned.
The six questions to ask before ordering
The price of an NFC card ranges from three to forty euros depending on the supplier, for an object whose manufacturing cost is roughly the same everywhere. So the difference is not in the chip. It lies in what is at the end of the address, and in the following six points.
1. Is there a subscription? Many sell the card at cost and then charge for the page, every month. The maths seems painless in the first year; it no longer is when you have equipped fifteen people and stopping the direct debit switches off fifteen cards already handed out. Ask what happens the day you stop paying.
2. Who owns the address? If the chip points to some-random-supplier.com/u/48219, your cards live only as long as that supplier. This market is young and sees many short-lived players come and go. Look at how long the domain has existed, and what the company behind it looks like.
3. Can a card be reassigned? One sales rep leaves, another arrives. If the encoded address contains their name — /martin-durand — the card leaves with them. If it is neutral, the same physical card serves their replacement without reprogramming. In a team with turnover, that is the difference between buying cards every year and never buying them again.
4. Can you make changes yourself? Some suppliers keep control of the profiles and charge for every change. Check that you — and ideally each employee for their own profile — can correct a number without raising a ticket.
5. Is the page indexed by search engines? It should not be. These are your employees' personal contact details: they belong at the end of a card they handed over, not in the search results for their name. An unguessable address and exclusion from search engines are the minimum.
6. What do you get back if you stop? The question nobody ever thinks to ask. At the very least, an export of your profiles.
Our cards cost €5 each, with no subscription, and the encoded address never contains the holder's name — which is what allows a card to be reassigned to a replacement.
See how they workThe key takeaways
An NFC business card is a simple object: an antenna, a chip and an address. All its value lies in what is at the end of that address, and so does all its risk. The technical questions — which iPhone, what range, how much memory — are settled in five minutes and have never wrecked a purchase.
What wrecks a purchase is discovering eighteen months later that a subscription controls cards already handed out, or that a departing sales rep takes their card with them because their name was encoded in it. Both points can be checked before ordering, with two questions.