Valerii Didur

“NFC tag detected” means your phone’s NFC reader found a chip within about two centimeters of it and could not work out which app should open it — so it asked you instead. Nothing was installed, nothing was charged to you, and nothing is read or shared unless you tap the notification. The chip is passive: no battery, no GPS, no connection of its own.

If you came only for the off switch: on Android it is Settings → Connected devices → Connection preferences → NFC, toggled off. iPhone has no NFC toggle, but it does let you silence the alert — swipe left on the notification, tap Options, then Mute or Turn Off. Full steps for both, with Apple’s own wording, are further down.

To find your LinkedIn QR code, open the LinkedIn mobile app, tap the QR code icon in the search bar at the top of your home screen, and open the “My code” tab. From there iOS can “Share my code” or “Save to photos”, and Android can “SAVE TO GALLERY” — LinkedIn lists sharing itself as coming soon on Android. The code points at your LinkedIn profile and nothing else: it carries no phone number, no email and no booking link, it brings nothing back from the person who scans it, and LinkedIn may ask a signed-out visitor to log in before showing your full profile.

That code is a shortcut into the largest professional network on earth — LinkedIn puts its community at 1.3 billion members, over 290 million of them in North America. LinkedIn’s mobile interface changes, though, and guides to it go stale quietly. Every label below was checked against LinkedIn’s own help documentation on August 14, 2026.

A vCard is the standard file format for an electronic contact card. It is saved with a .vcf extension, travels as plain text under the MIME type text/vcard, and holds one person’s name, phone numbers, email addresses, employer, job title, postal address, website, and optionally a photo — every line wrapped between BEGIN:VCARD and END:VCARD. Because every phone, mail client, and CRM on the market can read one, a .vcf is what almost every “save to contacts” button actually hands over, including the one behind a QR-code business card.

This guide is about that file — not the trading card game that shares the name. What is inside a .vcf, how the three living versions of the format differ, why a contact sometimes arrives without the photo or the job title, and what a QR code can and cannot carry.

To add your digital business card to your email signature, copy your card’s permanent link and paste it into your mail client’s signature editor: in Gmail, Settings → See all settings → Signature; in new Outlook and Outlook on the web, Settings → Accounts → Signatures; in Apple Mail, Mail → Settings → Signatures. Add the link as a short line of text (“View my digital business card”), attach it to a button-style image, or place a small QR code next to it — then save and send yourself a test email. The person who receives it needs no app: your card opens in any browser.

That one-time setup turns your busiest channel into a card rack. An estimated 376 billion emails were sent and received daily in 2025, projected to reach 424 billion by 2028 — and a long-standing Radicati Group estimate puts the average business user at about 121 of them every day. You’re already sending the emails. The signature just makes every one of them carry your card.