How to Use NFC Tags with Home Assistant

Home Assistant has NFC tags built in. You create a tag in Home Assistant, write its tag URL to a sticker, and use "tag scanned" as the trigger for any automation. When a phone with the Home Assistant companion app taps the sticker, the automation runs — lights off, alarm armed, a scene started — wherever the tag is.

The tag doesn't hold the automation, just an ID. That's the clever part: you can change what a tag does in Home Assistant at any time without touching the sticker.

What gets written to the tag

A Home Assistant tag is a normal NFC tag holding one link in this format: https://www.home-assistant.io/tag/ followed by the tag's ID. The companion app recognises that link and reports the scan to your Home Assistant instance. A short link like this fits easily on an NTAG213 sticker.

Step 1: Create the tag in Home Assistant

• In Home Assistant, open Settings → Tags and add a tag
• Give it a name you'll recognise later, like "Bedside" or "Front door"
• Copy the tag ID

Step 2: Write it with NFC Wizard

The Home Assistant companion app can write tags itself. NFC Wizard is useful when you want a saved template, want to write the same tag to several stickers, or want to protect tags from being rewritten.

• Open Templates and choose Smart Home Automation
• Paste the tag ID from Home Assistant. The template builds the https://www.home-assistant.io/tag/… link for you
• Hold a blank sticker to your phone and write it
• Optional: password-protect the tag (Tag Tools → Lock → Set Password) so nobody can overwrite it

Step 3: Build the automation

• Create a new automation and choose the Tag trigger
• Pick the tag you created
• Add your actions: turn off lights, set a scene, start the coffee machine, arm the alarm
• Save, then tap the sticker with your phone to test

iPhone and Android differences

Both work with the companion app installed and signed in. Newer iPhones (XS and later) read tags in the background without opening an app first. On Android, if a tag is blank or unrecognised, the phone may ask which app should handle it — written Home Assistant tags avoid that.

Ideas that stick

• Bedside: everything off, alarm armed, phone on Do Not Disturb
• Front door: "leaving" scene, heating down, robot vacuum starts
• Desk: focus lights and a work playlist
• Kids' rooms: a bedtime scene they can trigger themselves
• Garage or shed: lights on and the door status announced

One automation, several tags

Want the same action from more than one place — say, "goodnight" from either bedside table? Write the same tag ID to two stickers. If you use Bulk Write for that, turn auto-numbering off: it adds a serial to links, which would give each sticker a different URL.