How Backup Access Codes Work with Access Grants

Last updated: March 3, 2026

What are backup codes?

When you use Seam's Access Grants (the system behind Reservation Automations), backup codes ensure your guests can always access your property—even if your smart lock is offline when their scheduled access code needs to be programmed.

Backup codes are permanent codes that Seam programs onto your lock in advance. They sit unused until needed, like a spare key ready as a fallback.

This happens automatically—there's no configuration needed. Seam enables backup codes for all supported devices (all lock brands except Salto and lock models that have limited code slots).

When will my guests get a backup code?

For typical reservations (booked in advance)

If your lock is offline and can't program the scheduled access code, your guest will automatically receive a backup code 36 hours before check-in.

Example:

  • Guest checks in: Saturday at 3:00 PM

  • Backup code issued: Friday at 3:00 AM

  • Result: Guest has a working code well before arrival

For last-minute reservations

If a guest books close to check-in time and your lock is offline, Seam issues a backup code within minutes—not hours.

Example:

  • Reservation made: Saturday at 2:50 PM

  • Check-in time: Saturday at 3:00 PM

  • Backup code issued: By 2:55 PM (usually within 5 minutes)

Your guest gets their code almost instantly.

What do I need to do?

Make sure your lock has backup codes available

Your smart lock needs to be online periodically so Seam can program backup codes onto it in advance.

How it works:

  • When your lock is online, Seam automatically programs several permanent backup codes onto it

  • These codes remain unused until a guest needs one

  • When a scheduled code can't be programmed, Seam issues one of these pre-programmed backup codes to your guest

  • After checkout, that code returns to the available pool for the next guest

Monitor your backup code pool health

Seam surfaces three device-level signals about your backup code pool:

🔴 Error: empty_backup_access_code_pool

All 5 backup codes in the pool have failed to program on the device. No fallback is available—your guests won't receive access codes if your lock is offline.

🟡 Warning: partial_backup_access_code_pool

1–4 backup codes failed to program. The pool still works but is degraded. You should address connectivity issues soon.

🟡 Warning: many_active_backup_codes

More than 75% of the pool (>3 of 5 codes) are actively in use by guests. This means your lock is chronically offline and backup codes are being consumed faster than they're being replenished.

What if no backup codes are available?

If your lock has been offline continuously and never had backup codes programmed, the system can't provide a fallback. Your guest won't receive an access code.

To prevent this:

  • Ensure your lock comes online occasionally so Seam can refresh the backup code pool

  • Check your lock's battery and connectivity status regularly

  • Watch for warnings about low backup code availability in your Seam dashboard

For Developers

Check if a device supports backup codes

Check the supports_backup_access_code_pool capability on your device to see if it supports backup codes at all:

{
  "device_id": "...",
  "properties": {
    "supports_backup_access_code_pool": true
  }
}

This tells you whether the device type supports the feature—not whether backup codes are currently available on that specific device.

Track backup code issuance via webhooks

For Access Grants, look out for the access_method.issued or access_method.reissued events and check for is_backup_code: true in the event payload. The code field contains the backup code value your guest should use.

Example payload:

{
  "event_type": "access_method.issued",
  "access_method": {
    "code": "123456",
    "is_backup_code": true,
    ...
  }
}

Note: Backup codes are enabled automatically for all supported devices when you create an access grant. There's no additional configuration needed.