How does an NFC business card work? What is on the chip

The short answer: an NFC business card has a small chip and an antenna inside. It has no battery. When someone holds their phone close, the phone powers the chip by radio and reads one short message from it, usually a web link to your digital business card. The phone opens the link and the other person saves your contact. They need no app.

This guide explains what really happens in that tap, what you should store on the chip, and the small details that decide if your card works on every phone or only on some.

How an NFC business card works, step by step

NFC means Near Field Communication. The NFC Forum, the group that writes the NFC standards, describes it as a contactless radio technology on 13.56 MHz with “a typical range of up to 2cm”. It also says that “one side can also transmit power over the connection allowing for battery-less operating modes” (NFC Forum). That is why a card can work for years with no battery and no charging.

1. 1

   Step 1: The phone sends power

   An NFC phone sends out a weak radio field. When the card comes very close, its antenna picks up enough energy to wake the chip.

2. 2

   Step 2: The chip sends its message

   The chip sends back the data stored on it. On business cards this is an NDEF message, the standard format for NFC tags.

3. 3

   Step 3: The phone reads the record

   The phone looks at the first record in the message. If it is a web link, the phone shows it and opens it in the browser.

4. 4

   Step 4: The person saves your contact

   Your digital business card opens. The other person taps to save your details to their contacts, or follows your links.

NFC Forum tags are small memory cards that hold “a specially formatted data payload specified as an NDEF record (NFC Data Exchange Format)” (NFC Forum). Android works the same way: it reads NFC data in the form of NDEF messages (Android Developers).

What to put on the chip: a link or a vCard?

This is the most important choice, and many people get it wrong. You can write two kinds of data on an NFC business card chip:

The iPhone point decides it for most people. Apple says the iPhone reads tags in the background and then looks in the NDEF message for a URI record. Supported types are website links, email, SMS, phone, FaceTime and Maps links, and “if the NDEF message contains more than one URI record, the system uses the first one” (Apple Developer). A vCard is not on that list. So for a card that works on every modern phone, store one web link and put it first.

NFC business cards on iPhone and Android

iPhone. Apple says that “iPhone XS and later support background tag reading”, so no app is needed. The iPhone shows a small notification, and the person taps it to open the link. If the iPhone is locked, it asks the person to unlock it first. Background reading does not work when, for example, the camera or Apple Pay Wallet is in use, or in airplane mode (Apple Developer).

Android. Google says Android phones are “usually looking for NFC tags when the screen is unlocked, unless NFC is disabled in the device's Settings menu” (Android Developers). So the screen must be on and unlocked, and NFC must be turned on. Some people switch NFC off, so ask them to check if nothing happens.

Where to tap. The NFC antenna sits on the back of the phone, and the exact place differs by model. If nothing happens, move the card slowly over the back of the phone and hold it still for a second.

Metal NFC business cards: why they need a special build

A card of solid steel looks great, but metal and NFC do not mix well. NFC works with a magnetic field, and metal close to the antenna weakens it. The metal reflects the signal, takes energy from the field and creates small currents that work against it. The result is a shorter range or no read at all. The fix is a thin layer of ferrite between the antenna and the metal, which guides the field away from the metal (IoT For All).

• Buy metal cards made for NFC. They are built with this layer, or with the chip in a part of the card that is not metal. A normal NFC sticker on a metal card will often not work.
• Test before you buy many. Tap the card on an iPhone and on an Android phone. Try it through a phone case.
• Watch phone cases. A thick case, a case with a metal plate, or a magnet wallet on the back of the phone can block the read.

Common mistakes with NFC business cards

• No QR code on the card. Not every phone reads NFC in every situation. Print a QR code with the same link on the back, so every camera can open it.
• A vCard on the chip. It looks smart, but iPhones will not open it without an app, and you cannot update it. Use a link.
• A link you do not control. If the link points to a service you stop paying for, every card you gave out stops working. Use a link that you can keep and edit.
• The chip is not locked. Many NFC chips can be locked so nobody can write over your link. Lock it after you test it.
• Only NFC, no follow-up. A tap shares your details, but you do not get theirs. Ask for their card or badge too, so the contact goes both ways.

How to set up an NFC business card in 4 steps

1. 1

   Step 1: Create your digital business card

   Make one page with your name, job, company, phone, email and links. This is what people see after the tap. Read what a digital business card is if you are new to it.

2. 2

   Step 2: Write one link to the chip

   Store the https link to your page as the only record. Many cards come with the link already written, so you never touch the chip.

3. 3

   Step 3: Test on two phones

   Tap an iPhone and an Android phone, with and without a case. Scan the QR code on the back too.

4. 4

   Step 4: Use it at events

   Tap to give your details, and scan the other person's badge or card to get theirs. Our guide on how to capture leads at a trade show shows how teams do this at the booth.

NFC business cards from Swopi

Swopi NFC business cards open your Swopi digital business card with one tap. There are cards in basswood, matte black steel and gold, custom cards with your logo, and thin NFC stickers and tags for the back of your phone. Every card has a QR code too, for phones without NFC, and the other person needs no app. They get your contacts, social profiles, links and files. You change your details on your digital card, not on the chip. With the same app your team scans event badges and paper business cards, so the leads you meet go to your CRM without typing. Swopi connects to HubSpot, Salesforce and 5,000+ CRMs and apps. See pricing.