NFC with Home Assistant

NFC with Home Assistant

Home Assistant's NFC integration enables physical-world triggers for smart home automations — tap a tag by the door to arm the alarm, or tap a tag on the nightstand to run a bedtime scene. This guide covers setup via the Home Assistant mobile app, automations, and advanced integrations.

The NFC tags used are standard nfc-tag inlays — typically nfc-a (ISO 14443ISO 14443Standard for contactless smart cards at 13.56 MHz (Types A and B)View full →-A) chips such as NTAG213/215. The tag stores either a plain ndef-uri record that the HA app recognises, or a Home Assistant-specific ndef deep-link URL. The uid is used as the persistent identifier in HA's tag registry.

Integration Architecture

NFC Tag → Phone (HA Mobile App) → Home Assistant Core → Automation → Devices

The Home Assistant mobile app (Android and iOS) handles NFC scanning. When a tag is scanned, it fires a tag_scanned event in Home Assistant with the tag's ID and device name. Automations listen for this event to trigger actions.

Step 1: Register an NFC Tag

1. Open Home Assistant mobile app → ⋮ Menu → NFC Tags
2. Tap + → Add Tag
3. Hold phone near an NFC tagNFC tagPassive unpowered device storing data, powered by reader's RF fieldView full → to register its UID
4. Name the tag (e.g., "Front Door", "Nightstand")
5. HA registers the tag and stores its UID

Alternatively, tap an unregistered tag — HA mobile app prompts to register it automatically on first scan.

Step 2: Trigger an Automation from a Tag

In Home Assistant, create an automation with the tag scan as trigger:

# configuration.yaml or via UI
automation:
  - alias: "Bedtime Routine — Nightstand Tag"
    trigger:
      platform: tag
      tag_id: "abc12345-de67-89fg-hijk-lmnopqrstuvw"
    action:
      - service: scene.turn_on
        target:
          entity_id: scene.bedtime
      - service: alarm_control_panel.alarm_arm_away
        target:
          entity_id: alarm_control_panel.home

Finding your tag ID: After scanning in the HA app, the tag ID appears in Developer Tools → Events — look for tag_scanned events and note the tag_id value.

Step 3: Device-Specific Automations

The tag_scanned event includes the device that scanned the tag, enabling per-person automations:

automation:
  - alias: "Kitchen Tag — John's Phone"
    trigger:
      platform: tag
      tag_id: "kitchen-tag-uid-here"
    condition:
      condition: template
      value_template: "{{ trigger.device_id == 'johns_phone_device_id' }}"
    action:
      - service: scene.turn_on
        target:
          entity_id: scene.johns_kitchen_preference

This allows the same physical tag to trigger different scenes for different family members.

Common NFC Automation Recipes

Write Tag Action (Mobile App → Tag)

HA mobile app can write to NFC tags — useful for encodingencodingData writing to NFC tags during manufacturing productionView full → the HA-specific deep link URL:

1. HA app → NFC Tags → select a registered tag → Write Tag
2. The app writes an NDEF URI recordURI recordNDEF record encoding URIs with compact prefix compressionView full →: https://www.home-assistant.io/tag/{tag_id}
3. When any HA app user scans this tag, it fires the tag_scanned event automatically

This URL is recognised by the HA app on any phone — even devices that haven't pre-registered the tag. It does not work in a browser (it requires the HA app).

Advanced: NFC Tag Presence Detection

For room presence detection, place tags at strategic locations and build a input_select or device_tracker that updates when tags are scanned:

input_select:
  family_location:
    name: "Family Location"
    options:
      - Kitchen
      - Living Room
      - Bedroom
      - Away

automation:
  - alias: "Update location — Kitchen tag"
    trigger:
      platform: tag
      tag_id: "kitchen-tag-id"
    action:
      service: input_select.select_option
      target:
        entity_id: input_select.family_location
      data:
        option: Kitchen

Integrating with Tasker and Shortcuts

If you prefer a more powerful automation app on the phone side, use Tasker (Android) or Shortcuts (iOS) to call the HA REST API directly instead of using the HA mobile app NFC integration:

Tasker NFC trigger → HTTP POST to HA REST API
  POST https://homeassistant.local:8123/api/events/tag_scanned
  Headers: Authorization: Bearer {token}
  Body: {"tag_id": "my-tag-id"}

This fires the same tag_scanned event as the HA mobile app, keeping all automation logic in HA while using Tasker for advanced mobile-side logic.

See NFC Tasker for Android and NFC Apple Shortcuts for device-side automation guides.

Troubleshooting

See Also

• NFC Smart Home Automation
• NFC Tasker for Android
• NFC Apple Shortcuts Automation
• NFC Tag Form Factors
• Compatibility Checker