NFC business cards explained: the tag, the URL and who writes what

An NFC business card is a piece of plastic with a sticker-sized chip in it. The chip has no battery, no processor worth the name, and in a typical card a few hundred bytes of memory. It does one thing: when a phone's field powers it, it hands over a short block of data.

That data is almost always a URL. Everything interesting about NFC cards follows from how small that block is and who controls what it points at.

What is actually on the tag

The format is NDEF, the NFC Forum's data exchange format. A card carries one NDEF message with, usually, one URI record.

URI records are compressed in a small but useful way: the first byte is an abbreviation code for a common prefix, so https:// costs one byte instead of eight. What follows is the rest of the URL as plain text.

The common chips used in cards — the NTAG21x family — carry 144, 504 or 888 bytes of user memory depending on the part. That is plenty for a URL and nowhere near enough for a photograph, which is the first thing people ask.

On the tag	Size	Editable after printing
A short link	Around 20 bytes	Yes — change the destination, tag untouched
A full profile URL	40–80 bytes	Only by rewriting every card
A vCard written directly	200–600 bytes	No

The middle row is where most cards land, and it is the row that ages badly.

Why a short link matters more here than anywhere else

Everywhere else, shortening is about legibility. On an NFC card it is about the tag being a pointer rather than a record.

A tag holding https://yourcompany.com/team/priya-sharma is correct until Priya changes teams. A tag holding a short link is correct forever, because the destination behind it is a field in a database.

The same argument applies to a vCard written straight onto the chip. It is the most tempting option — the phone offers to save the contact with no page load at all — and it is the one that turns a box of five hundred cards into landfill when a phone number changes.

What gc.mw provides, precisely

We do not sell cards, we do not write tags, and there is no NFC feature in the product. What we provide is the thing a tag should point at.

A bio page at gc.mw/@name holds your details, your links and a Save contact button. gc.mw/@name.vcf downloads a vCard built on the server, so a phone number you have chosen to keep private is never in the file. gc.mw/@name.qr is the QR code for the same page.

Any short link works the same way: create it, point it at whatever you like, and hand the URL to whoever manufactures the cards. The tap is then an ordinary visit — counted, attributed, and pointing wherever the link currently points.

Getting a card made

1. 1

   Decide what the tap should do

   Open a profile page, or save a contact immediately. The first is more useful, because a page can hold links and a contact button; the second is faster but is one action and no more.

2. 2

   Create the destination and check it on a phone

   Load it on a real phone over mobile data, not on your laptop. This is where a slow page or a broken photo shows up.

3. 3

   Hand the supplier the short link

   Not the final URL. The tag then never needs rewriting, whatever changes later.

4. 4

   Ask for locked tags and a printed QR on the same card

   Locked so nobody can repoint them, and a QR because NFC does not work for everyone. Both are usually free at manufacture and impossible to add afterwards.

5. 5

   Order five before you order five hundred

   Test on an old Android, a recent iPhone, and one phone in a case thick enough to matter.

The honest limitations

NFC needs the phone held within a couple of centimetres, near the antenna, which is in a different place on every model. It fails silently — nothing happens, and the person you handed the card to concludes it is broken and does not tell you.

That is the real argument for the QR code on the same card, and for keeping the printed name and number legible. NFC is a nice interaction when it works and invisible when it does not. Design the card so the failure costs nothing.

The page behind the tap is the part worth the effort: see link in bio for the themes, the blocks, the vCard download and the analytics that tell you whether the cards are being used at all.