Learn › Chapter 6 of 11

Chapter 6 · Backups that survive

Your Bitcoin Backup Won't Survive a House Fire (Here's the Fix)

Prefer to watch? This chapter is also a short video (about 4½ minutes). The full text is below.

In one minute: Your recovery words are the money, so the piece of paper they're written on is the most important object in your house. Paper burns and water ruins it; words stamped into steel or titanium survive a house fire. One copy is a single point of failure, so keep two, in two different places, never next to the device. Then test your backup before you need it, because a backup you've never tried is only a hope. And if your words were ever typed, photographed or seen, the fix is simple: make new ones and move your bitcoin.

Most people's recovery words are on the little paper card that came in the box. And most of those cards are in the same drawer as the device.

Go back to the table in Chapter 3. Device gone, words safe: you're fine. Device safe, words gone: one accident away. Both gone: the bitcoin is gone for good.

A drawer that holds both is one kitchen fire away from that last row. U.S. fire departments responded to about 1.39 million fires in 2024. ¹

This chapter is about making sure your words outlive anything that can happen to your house.

What a backup has to survive

• Fire. The most obvious one.
• Water. Burst pipes, floods, and the firefighters' hoses.
• Time. Ink fades, paper yellows, and a card in a damp basement grows mildew.
• Forgetting. "I put it somewhere safe" is how a lot of bitcoin gets lost.
• The wrong person finding it. A backup that's easy to find is easy to steal.

Paper burns. Metal doesn't.

An average house fire burns at around 1,100°F. ² Paper doesn't last anywhere near that long, and even a card that escapes the flames can be soaked by the water used to put them out.

That's why serious backups are made of metal: your words stamped, punched or etched into stainless steel or titanium. One bitcoin security researcher has spent years attacking dozens of metal backup products with torches, hammers and salt water. A few lessons from those tests: ²

• One solid piece beats many small parts. Designs that spell words with lots of little tiles can come apart or warp in a fire and scramble the order.
• Marks made into the metal itself hold up best. Punched dots or etched letters are part of the plate, so they can't fall out. Stamping whole letters with a punch set works, but it's slow and easy to get wrong.
• Thicker is safer. He suggests at least 5 millimeters, about a fifth of an inch, so the plate doesn't bend or melt.

You don't need an expensive product. A plain stainless steel plate and a hand punch from a hardware store will do. The Beginner level walks through it step by step.

One copy is not enough

A single backup, however strong, can still be lost, stolen, or buried under a collapsed house. So:

• Make two copies of the same words.
• Keep them in two different places, far enough apart that one event can't reach both. One might stay at home, somewhere other than next to the device. The other might go to a trusted relative's home, or a bank safe deposit box.
• Know that a safe deposit box isn't insured. The FDIC, which insures your bank account, doesn't insure safe deposit boxes or what's in them. ³ It's still a good place, but it's not a guarantee, and someone in your family needs to be able to get into it (that's Chapter 7).

A few things not to do:

• Don't keep the words next to the device. Someone who finds both has everything.
• Don't split the list in half and store the halves in different places. If either half is lost, so is the bitcoin, and anyone who finds one half has a big head start on guessing the rest. There are better ways to split up trust; they're in the Advanced level.
• Don't make a digital copy. No photos, no cloud, no notes app, no password manager. Metal and paper only.
• Don't label it for a stranger. Nothing that says "BITCOIN" in big letters. Your family plan in Chapter 7 is where you'll tell the right people what it is.

Test it before you need it

A backup you've never tested is a hope, not a plan. A misspelled word or a skipped line can lock you out, and you'd never know until the day you need it.

The test is called a recovery drill: you prove that your backup, and only your backup, can bring your wallet back.

1. Before you put real savings on a new device, or on a spare device you're comfortable resetting, write down the first receiving address the wallet shows you.
2. Reset the device (or use the spare) so it holds nothing.
3. Restore it using only your metal backup, typing the words in on the device itself.
4. Check that it shows the same first receiving address. If it does, your backup works.

Many devices also have a built-in "check my backup" option that asks you to enter your words on the device and confirms they match. Either way: do it once now, and again whenever you make a new copy.

If your words were ever exposed

If your words were ever typed into a phone or computer, photographed, saved online, or seen by someone who shouldn't have seen them, you can't make them secret again. But you can make them worthless:

1. Set up a wallet with brand-new words, and back those up properly this time.
2. Send your bitcoin from the old wallet to the new one.
3. Once it arrives, the old words control nothing.

It takes an evening, and it closes a door that would otherwise stay open forever.

Talk about it

1. How many copies of our words exist right now, and where is each one?
2. Could one fire, flood or burglary take all of them, or the words and the device?
3. Have we ever tested that our backup actually works?

If the honest answers are "one," "yes," and "no," you're in the same place as most families. Fixing it is a weekend project.

Sources