BitBox02 Backup: microSD Card and Recovery Words

By Simon Bumford, Founder · 2026-07-29 · 10 min read

How the BitBox02 backup works: the instant microSD card backup, optional recovery words, restore steps, and how to keep it all safe. A plain English UK guide.

How do you back up a BitBox02?

You back up a BitBox02 by inserting the microSD card that comes in the box and confirming the backup on the device's own screen during setup. It takes moments, and there is nothing to copy out by hand. That is the BitBox02's signature convenience: most hardware wallets make you transcribe 12 or 24 seed words before you can do anything else. You can also ask the device to display those recovery words later and write them down as a second copy, and we recommend you do exactly that. Either the card or the words can bring your bitcoin back on a new device if yours is ever lost, stolen or broken. Lose both, and nobody on earth can recover the coins, including the manufacturer. This guide walks through the card backup, the words, where to keep everything, how a restore works, and whether the newer BitBox02 Nova changes anything. If you are still deciding which device to buy, our plain English guide to how to back up a hardware wallet covers the principles that apply to every brand.

How it works: your backup is keys, not coins

A backup does not contain bitcoin. Your coins live on the Bitcoin blockchain, a shared public ledger, and they never leave it. What your BitBox02 holds, and what your backup copies, is your private keys: the secret information that proves the coins are yours and authorises spending them. This is why one small card can back up any amount of bitcoin, and why losing the device itself is not the disaster people imagine. The device is replaceable hardware. The keys are the thing. It is also why a backup deserves more care than the device. Your BitBox02 asks for a password before it unlocks. Your backup does not: anyone who gets hold of it can recreate your wallet and spend your coins without ever touching a BitBox02. So the same rules apply to the microSD card and the written words alike. Never type recovery words into a computer or phone. Never photograph them. Never store them in email, cloud drives, notes apps or a password manager. Handwriting, paper and a private place: dull, old fashioned and exactly right.

How to create a BitBox02 microSD card backup

The card backup happens during first setup, and it is deliberately hard to get wrong. Install the BitBoxApp, connect your BitBox02 (or pair a Nova with your phone), choose a device password, then insert the microSD card from the box when prompted, pushing gently until it clicks. The device asks you to confirm today's date on its own screen, and the backup is written to the card in seconds. Eject the card and put it somewhere safe. It should not live in the device or in the same drawer. You can create a fresh backup whenever you like from the settings in the BitBoxApp, and Shift Crypto publishes a clear official walkthrough if you want screenshots. Making a second card backup on a spare microSD card, kept in a different location, is a cheap upgrade worth doing once you are comfortable. Two habits to build from day one. Verify anything important, such as a receive address, on the device's own screen rather than trusting the computer. And when you first move coins to the wallet, send a small test amount before the full balance.

Should you also write down the recovery words?

Yes, and here is why. A microSD card is tiny, losable and, like all electronics, not guaranteed to last decades. The recovery words are your universal fallback: the BitBox02 can display them on its own screen, they follow the BIP39 standard, and they can restore your wallet on a replacement BitBox02 or on other compatible wallets. Two different formats in two different places is a far stronger position than one card in one drawer. Do it properly, once. Sit somewhere private, write the words by hand on paper in the exact order the device shows, and check every word twice. The words must never exist anywhere digital: no photo, no typing them into a computer or phone to keep a copy, no cloud storage, no password manager. Each of those turns an offline secret into something hackable from anywhere in the world. Then store the card and the paper in separate places, away from the device, somewhere a burglar would not look and a flood would not reach. Do not label either one bitcoin. If you want to go deeper on storage trade-offs and what we consider good practice, our security overview covers it.

What happens if you lose your BitBox02 (or the card)?

Run the scenarios now, calmly, so none of them can panic you later. You lose the device but have a backup: nothing of value is lost. Your coins sit untouched on the blockchain, and either the card or the words will restore them to a new device. A thief who takes the BitBox02 itself still faces its password protection, but treat the event seriously: if you have any doubt, restore your wallet on a new device and move the coins to a fresh wallet. You lose the card but still have the device: your coins are fine, because the keys remain on the BitBox02. You are, however, one accident away from real loss. Make a new backup immediately, on a new card or by writing down the recovery words, and find a better hiding place this time. You forget the device password: annoying, not fatal. Reset the device and restore from your backup, which is one more reason the backup matters even while everything works. You lose the device and every backup: the coins are gone. There is no reset email, no support ticket, no company that can help. Everything else in this article exists to make this scenario impossible.

How to restore your BitBox02 from a microSD card backup

A restore is the setup process in reverse, and practising the logic now saves stress later. On a new or factory reset BitBox02, the BitBoxApp offers to restore an existing wallet. Insert your backup card, pick the wallet backup shown, confirm on the device screen and set a new device password. Shift Crypto's official restore guide shows each step. If you have no card but do have the recovery words, choose the restore from recovery words option instead and enter them on the device itself, never on the computer. Two checks before you trust the restored wallet with everything. First, generate a receive address, verify it on the device's own screen, then send a small test amount and confirm it arrives. Second, check the balance and transaction history look right. Only then return to normal use. One quiet warning: a restore is the moment scammers pray for. If you ever find yourself on a website or in an app asking you to type your recovery words to restore or validate your wallet, you are being robbed. Recovery words go into hardware wallet devices, nothing else.

BitBox02 or BitBox02 Nova: does the backup change?

The BitBox02 Nova, announced in June 2025 and shipping since that summer, is the newer of the two models Shift Crypto currently sells, and the backup routine is reassuringly unchanged: instant microSD backup at setup, optional recovery word display for your handwritten copy, and the same restore paths. What changes is connectivity and price. The Nova adds iPhone and iPad support over Bluetooth, using a protocol called Whisper that runs on a separate memory-less chip, and it carries an EAL6+ certified secure chip. It costs about $159.20 on the official shop. The original BitBox02, launched in 2019, costs about $136, connects over USB-C, and works with desktop computers and Android phones but not iPhones. Both are sold in a Bitcoin-only edition, which strips out other coins to reduce attack surface; if you only hold bitcoin, choose that one. Neither model is air-gapped: they connect by USB or Bluetooth rather than passing everything through QR codes. For most people this is a sensible trade for ease of use, but if a fully air-gapped signer appeals, read our guide to backing up a Coldcard before deciding.

Shift Crypto, data leaks and the phishing rule

The BitBox02 is a Swiss hardware wallet from Shift Crypto AG in Zurich, founded in 2015 by Douglas Bakkum, with Bitcoin Core developer Jonas Schnelli closely involved during the BitBox02 era. The firmware is fully open source, there is a public bug bounty, and the company's disclosure record is genuinely good: when a researcher privately reported a firmware flaw in 2020 that could trick a user into overpaying transaction fees, it was fixed in an update with no funds lost. The blemishes are data leaks, not device failures. In 2022 the company's account at a third-party marketing platform was compromised, leaking newsletter data such as names, email addresses and order numbers, as covered in Shift Crypto's own disclosure. In July 2025 the Everest ransomware group claimed a breach of order data covering more than 20,000 customers, later reported leaked on a hacker forum. In neither case were devices, keys or funds affected. The practical lesson applies to every brand: criminals who learn you own a hardware wallet will email you pretending to be the maker. Trezor and Ledger customers have been phished the same way after those companies' own leaks. Treat every email from a wallet company as potential phishing, and remember that no legitimate company will ever ask for your recovery words.

Who the BitBox02 suits, and where to buy it in the UK

Our honest read: the BitBox02 is one of the best choices for a UK holder who wants serious self-custody with the least fiddly setup. The instant card backup removes the step beginners most often get wrong, the app holds your hand without hiding what matters, and the Swiss maker has a solid record of fixing and disclosing problems. It is not the wallet for air-gap purists, and the small display will not suit everyone: the Nova uses a compact gesture-based screen and the original has a tiny OLED with touch sliders, rather than a large touchscreen. If your coins are currently sitting on an exchange, moving them is the natural next step after setup; our guide to moving bitcoin from Coinbase to a hardware wallet walks through it safely. Buy only from the official shop, which ships to the UK and supports GBP at checkout, or from official channels such as the Amazon.co.uk listing and UK resellers like Monix and BTC Direct. Never buy second-hand: a tampered device can be rigged in advance to steal everything you load onto it. And given the 2025 order-data leak, consider delivery to a collection point rather than your home address.

The backup that survives you

There is one failure mode this article has not yet covered, and it is the most common serious one we see: the backup that works perfectly but that nobody else can find or use. If you died tomorrow, or lost capacity, would your family know the microSD card in the loft is not just an old camera card? Would they recognise 24 handwritten words as an inheritance rather than clutter? Would they know the coins exist at all? A backup protects your bitcoin from a lost device. It does not protect your family from losing you. That takes a small amount of planning: making sure the right person knows what exists, where to find it, and who can help them use it, all without handing anyone the ability to spend your coins today. Our guide to crypto inheritance planning explains how to set this up properly, and the free inheritance scorecard takes a few minutes and shows you exactly where the gaps are. Do it while it is easy.