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 14443-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 tag 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 encoding the HA-specific deep link URL:

1. HA app → NFC Tags → select a registered tag → Write Tag
2. The app writes an NDEF URI record: 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