Keep it safe

In short · 5 points

1. 01Whoever holds the private keys controls the bitcoin. If a provider holds them for you, you have a contractual claim against it.
2. 02Mt. Gox, Celsius and FTX show what happens in a collapse: customers waited for years, and FTX paid out dollars at the bankruptcy-date price instead of bitcoin.
3. 03In Germany, crypto assets held in custody are deemed to belong to the customer under § 45 KMAG. That helps in an insolvency, but doesn’t protect you from hacks, frozen accounts or lengthy proceedings. There is no deposit guarantee.
4. 04Self-custody means full control and full responsibility: if your seed phrase is lost, nobody can help you.
5. 05The four-level model (0–3) leads step by step from a provider to your own hardware wallet.

In short · 5 points

1. 01An app wallet takes 20 to 30 minutes to set up. You need some quiet, pen, paper and a small test amount.
2. 02Download the app only from the official store or via the project’s website, and check the developer name.
3. 03The seed phrase (usually 12 or 24 words) is the master key: write it on paper only, never photograph it, never share it with anyone.
4. 04The PIN only protects the app on this phone. If the phone is lost, only the seed phrase helps.
5. 05Before every payment, compare the address, send a test amount first, then practise recovery once.

In short · 5 points

1. 01The seed phrase is the master key to your bitcoin. Anyone who knows it can move everything. If you lose both it and your device, you can’t get back in.
2. 02Never digital: no photo, no screenshot, no cloud, no password manager, no email.
3. 03Paper is enough for small amounts. For more, steel is better: in a stress test with fire, acid and a 20-ton press, simple steel plates offered the best value for money.
4. 04Keep at least two copies in separate places, without a ‘Bitcoin’ label.
5. 05Don’t split the words into halves. To distribute a backup, use Shamir backup or multisig.

In short · 5 points

1. 01A wallet holds keys, not bitcoin. The device can be replaced, the seed phrase cannot.
2. 02The most important distinction is hot or cold: are the keys on a device with an internet connection or not?
3. 03Mobile wallets suit small amounts and everyday use, hardware wallets suit savings, and desktop wallets work as a control centre. Paper wallets are considered outdated.
4. 04Bitcoin-only means less code and so fewer potential bugs. Multi-coin wallets hold bitcoin on the same principles.
5. 05A proven combination: a purse on your phone and a safe for your savings.

In short · 4 points

1. 01The passphrase is an addition to the seed phrase that you choose freely. Every passphrase produces its own, completely different wallet.
2. 02Benefit: anyone who finds only your seed phrase can’t get at the funds in the passphrase wallet. It also makes a decoy wallet possible.
3. 03Risk: forget it and it’s gone. A typo opens an empty wallet without any warning, and nobody can reset the passphrase.
4. 04Write it down exactly and keep it separate from the seed phrase. You don’t need a passphrase to get started.

In short · 5 points

1. 01Test recovery while only a small amount is in the wallet. After that, a backup check about once a year and before firmware updates is enough.
2. 02Some hardware wallets check your backup without wiping the device. A trial recovery is more thorough.
3. 03If a restored wallet looks empty, the money often isn’t gone. Common causes: wrong address type, the gap limit, a missing passphrase or a different backup format.
4. 04Backup lost, seen or stored digitally? Create a new wallet and move your funds.
5. 05Anyone offering to ‘recover’ lost bitcoin for a fee is almost always a scammer. Never hand over your seed phrase.

In short · 5 points

1. 01All Bitcoin transactions are public and permanently visible. The only thing that stays private is who owns an address – until it’s linked to your name.
2. 02Chain analysis links addresses using patterns such as common inputs and change. A single known address can give away many more.
3. 03Your exchange knows your name and your withdrawal addresses. In the EU, since 2026 it has been recording purchases, sales and transfers to external addresses such as your own wallet, and reports them annually, first in 2027 (DAC8). Self-custody doesn’t mean invisibility.
4. 04The most effective habits: a new address for every payment, label your coins and select them deliberately with coin control, never show your holdings publicly.
5. 05Privacy is legal and protects you from thieves and scammers. Your tax obligations remain unaffected.

In short · 5 points

1. 01All good hardware wallets keep the keys offline and sign payments inside the device. They differ in how they secure this.
2. 02Four criteria help you compare: open-source code, a security chip, an air gap and an easy-to-read display – plus whether you store only bitcoin.
3. 03Many incidents were data leaks and phishing at shops and service providers; there were also flaws in firmware and chips – including at manufacturers we earn from. The COLDCARD bug in 2026 led to stolen funds.
4. 04More important than the model: buy from the manufacturer, keep the backup safe and check every address on the device.
5. 05We receive a commission on purchases made via links marked as ads (with *) – which manufacturers that currently applies to is listed under ‘How we earn money’. We present all manufacturers by the same standards.

In short · 5 points

1. 01Almost every scam follows the same pattern: build trust, apply pressure, demand a payment or your seed phrase. Bitcoin payments can’t be recovered afterwards.
2. 02The costliest scheme in the FBI’s statistics is crypto investment fraud via chats, dating apps and fake platforms: around $7.2 billion in reported losses in the USA in 2025.
3. 03No one legitimate will ask for your seed phrase – no support team, no exchange, no authority and not us either.
4. 04‘Taxes’ or ‘fees’ before a withdrawal, and offers to recover lost money, are typical signs of a scam.
5. 05If the worst happens: pay nothing more, break off contact, change passwords, move any remaining funds to a new wallet, inform the police and your financial regulator (in Germany, BaFin).

In short · 5 points

1. 01Legally, your relatives also inherit your bitcoin. With self-custody, though, they can only get at it if they know it exists and find the backup.
2. 02An emergency letter says which wallets and accounts exist, where the documents are and who can help – it never contains the seed phrase, passphrase or PINs.
3. 03The seed phrase doesn’t belong in your will: in Germany, the probate court opens it and notifies the parties involved in writing of the parts that concern them.
4. 04Depending on the amount, this ranges from backup plus letter to multisig or a timelock. What matters is that your family can operate the system.
5. 05Tax in Germany: personal allowances, notification to the tax office generally within three months, and the holding period doesn’t start again (as of September 2026). Not tax advice.

In short · 5 points

1. 01A hardware wallet generates your keys offline and signs payments itself. The key never leaves the device.
2. 02Buy only from the manufacturer or an authorised reseller. If a filled-in word list is included, it’s a scam.
3. 03Protect your data when you buy: shops and service providers used by manufacturers have had several data leaks. A parcel locker and a separate email address help.
4. 04When setting up: check the seal, confirm firmware and authenticity via the official app, seed phrase only on paper or metal, PIN on the device.
5. 05Check every receiving address on the device’s display and send a test amount first.

In short · 5 points

1. 01With multisig, a payment needs several signatures. With 2 of 3, there are three keys and two are enough.
2. 02If one key is lost or stolen, your funds aren’t gone: no single device or backup can move anything.
3. 03The price: more devices, backups and procedures, slightly higher fees, no Lightning. Multisig is for large amounts, not for getting started.
4. 04As well as the seed phrases, you have to back up the wallet configuration (the descriptor or all xpubs). Without it, you can’t spend even with enough keys.
5. 05Software such as Sparrow or Nunchuk coordinates the devices. The keys are best kept on hardware wallets from different manufacturers.

In short · 5 points

1. 01Three levels: Basic applies to everyone, Advanced once you have your own hardware wallet, Significant holdings for amounts whose loss would hit you hard.
2. 02The most important points cost almost nothing: a separate password for each account, a second factor via app or security key instead of SMS, and your seed phrase only on paper or metal, never passed on.
3. 03With a hardware wallet, habits count: check the address on the device, keep the firmware up to date, test recovery once.
4. 04More protection brings more complexity. Only set up what you understand yourself and can explain.
5. 05A short security review once a year is worthwhile.