NFC Guide

How to Write and Program an NFC Tag: Step-by-Step Guide

An NFC tag is blank until you write data to it, and writing one is simpler than most people expect — no special reader/writer device required, just a phone.

Here's exactly what "writing" a tag means, what you need, and how to do it.

What Does "Writing" an NFC Tag Actually Mean?

A blank NFC tag is just a small chip with a tiny amount of memory. Writing to it means storing a piece of data — usually a URL — that a phone reads the instant it taps the tag. For a digital business card, that URL points to your live profile.

What You Need

An NFC-enabled smartphone (most Android and iPhone models from 2018 onward)
A blank or rewritable NFC tag or card
An app that can write to NFC tags — Cardly NFC Scanner has this built in, so you don't need a separate NFC-writing app

How to Write an NFC Tag (Step by Step)

1
Open your NFC writing app and select "Write to Tag."
In Cardly NFC Scanner, this is built into your profile screen.
2
Choose what the tag should open.
Your profile link, review link, or any URL you want.
3
Hold your phone's NFC antenna against the blank tag.
The antenna is usually near the top-back of the phone; hold it in place until you get a confirmation.
4
Test it.
Tap the tag with a second phone to confirm it opens the right link.

Can You Rewrite or Reset an NFC Tag?

Yes — most NFC tags, including the ones used for Cardly NFC Scanner cards, are rewritable, not one-time-use. If you change your profile link or want to repurpose a tag, you can write new data over the old data. That's what "resetting" a tag means in practice.

Common Problems When Writing NFC Tags

Tag not recognized — move the phone slightly; most antennas sit in a specific spot on the back of the phone, not dead-center.
Tag is locked — some tags can be locked to prevent further writes; check if yours was intentionally locked before assuming it's broken.
Data doesn't open automatically — confirm NFC is turned on in your phone's settings, and that you tapped with the screen unlocked.

Why This Matters for Your Digital Business Card

Being able to write, rewrite, and reset your own NFC tags means your Cardly NFC Scanner card never becomes obsolete. Change jobs, update your number, or repoint the tag to a different link entirely — all without buying a new card.

Frequently Asked Questions

Do I need special equipment to write an NFC tag?

No — a modern smartphone is enough; you don't need a dedicated NFC reader/writer device.

Can I write an NFC tag with an iPhone?

Yes, iPhones from the XS/XR generation onward (iOS 13+) support both reading and writing NFC tags.

How much data can an NFC tag store?

Most business-card-sized tags store enough for a single URL, which is all a digital business card needs, since the URL points to a live profile that can hold unlimited information.

Can someone else overwrite my NFC tag without my permission?

Only if they have physical access to the tag and a compatible app — you can lock a tag to prevent further writes if you want it to be permanent.

What happens if I write the wrong link by mistake?

Simply write over it again with the correct link, as long as the tag isn't locked.

Write Your First Card

Set up your profile and write your first NFC tag in a couple of minutes.

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