TL;DR
Once a year: open each box, check the backups on the devices, update firmware, rehearse a recovery from one of the boxes, and check your inheritance letter still matches reality. Put it in your calendar now.
Why bother
Steel doesn’t rot, but people move house, boxes get shifted, USB sticks die, passwords get forgotten and apps change their menus. Once a year is enough to catch these before they matter.
The routine
- Boxes: visit each location. Check the plates, the passphrase card, the USB stick and the silica gel. Replace damp gel and anything damaged. Check one plate at a time: take the device to the box, or bring one plate home and put it back before fetching the next. Never have two plates away from their boxes at once.
- Seeds: check each plate on its own device: Check Backup on the Trezor, Recovery Check on the Ledger, Show recovery words on the BitBox02 (step 5).
- Firmware: update each device through its maker’s app, then check that Sparrow still shows the same fingerprints. See firmware updates.
- Recovery: import the descriptor from one box’s USB stick into a fresh Sparrow and compare addresses (step 10).
- Addresses: show a receive address on the BitBox02 or Ledger and compare it with Sparrow.
- Letter: read your inheritance letter. Still accurate? Update it if anything moved.
- Notes: write the date and what you did in your log.
The checklist PDF has a page for these notes.
When to check sooner
- After moving house or changing where a box is kept.
- After a security alert about one of your devices.
- When someone who keeps a box for you moves, or can no longer do it.