To set up a self-custody crypto wallet, download the wallet from its official website or app store, choose to create a new wallet, write the seed phrase it shows you on paper, store that paper offline, and send yourself a small test amount before moving anything larger. The wallet does not hold coins. It holds the private keys that authorise transactions on the blockchain, and the seed phrase is the backup from which those keys can be restored. Anyone who has the phrase controls the funds, and without it lost funds are often impossible to recover.
Step by step: a self-custody wallet
- Pick the wallet type. Decide between a software wallet (mobile, desktop or browser extension) and a hardware wallet. The trade-offs are in the next section.
- Download or buy from the official source. For a software wallet, use the wallet's official website or the official app store. For a hardware wallet, never use a device that arrives with a recovery phrase or PIN already set up; a genuine device generates its own phrase during setup.
- Create a new wallet. Choose "create" rather than "import". This is the step in which the software generates your keys.
- Write down the seed phrase. It is usually 12 to 24 words, and the order of the words matters. Write it on paper (or a metal backup) and keep it offline.
- Set the device protections. Set the PIN or password the wallet asks for. A password protects against someone who picks up your device, but it cannot protect against keylogging software, and it is not a substitute for the seed phrase backup.
- Get your receiving address. Copy it from the wallet. On a hardware wallet, check that the address shown on the computer matches the address shown on the device's own screen.
- Send a small test amount. Send a small amount first and confirm it arrived before moving a larger sum. Transactions cannot be reversed.
Types of wallet and their trade-offs
Two separate questions define a wallet: who holds the keys, and whether the keys sit on a device connected to the internet.
Custodial vs self-custody
- Self-custody (non-custodial). You alone hold the keys and carry the full security responsibility. The wallet maker does not hold your funds and cannot restore your phrase. If the keys and the backup are lost, stolen or exposed, access can be lost permanently.
- Custodial. A third party holds the keys, and you sign in with a username and password that can be reset in the usual way. The trade-off is trust: if the custodian is hacked, shuts down or runs into financial trouble, your assets are at risk.
Hot vs cold
| Type | Where the keys live | Strength | Weakness |
|---|---|---|---|
| Mobile, desktop, browser extension (hot) | An internet-connected phone, computer or browser | Convenient for frequent use | More exposed to malware, phishing and other online threats |
| Hardware wallet (cold) | A dedicated device; the private key stays on it and signs transactions there | Keys never touch the internet | The device can be lost, damaged or stolen, so the seed phrase backup still decides whether funds can be recovered |
| Offline storage generally (cold) | A device or medium kept off the network | Highest security for savings | Less convenient to spend from |
A common split is to keep only small amounts in a wallet on your phone or computer for everyday use and the rest in offline storage.
Which wallet setup fits what you are doing?
Answer up to three questions to see which wallet type fits your use and the setup steps that matter most for it.
Do you want to hold the private keys yourself, or let a third party hold them?
- I want to hold the keys myself → next question
- A third party can hold them → Custodial account
What are the funds for?
- Small amounts for frequent, everyday use → Software (hot) wallet
- Savings I rarely touch → next question
- Both: some to spend, the rest to keep → Split: hot for spending, cold for the rest
If you use a hardware wallet, how did the device arrive?
- New, and it generates its own recovery phrase during setup → Hardware (cold) wallet
- It already had a recovery phrase or PIN set up → Do not use that device
A third party holds the keys and you sign in with a username and password that can be reset. The trade-off is trust: if the custodian is hacked, shuts down or runs into financial trouble, your assets are at risk.
Download it only from the official website or app store, choose create rather than import, write the 12 to 24 word seed phrase on paper and keep it offline, set a PIN or password, and send a small test amount first. Hot wallets are more exposed to malware and phishing, so keep only small amounts here.
Keep only small amounts in a wallet on your phone or computer for everyday use and the rest in offline storage. Each wallet needs its own seed phrase backup on paper or metal, with no screenshots or cloud copies.
The private key stays on the device and signs transactions there. Write the phrase it generates on paper or a metal backup, check that the receiving address on the computer matches the device's own screen, and send a small test amount first. The device can be lost, so the seed phrase backup still decides whether funds can be recovered.
Never use a hardware wallet that arrives with a recovery phrase or PIN already set up. A genuine device generates its own phrase during setup.
This points to a wallet type and its key setup steps only: it does not compare specific wallet products, check which seed standard a wallet uses, or cover passphrases, smart-contract approvals and recovery planning for family.
A user may decide to protect their mnemonic with a passphrase.
How the seed phrase works (BIP-39)
Most wallets that show a list of words follow BIP-39, a Bitcoin Improvement Proposal that defines how such a phrase, which the standard calls a mnemonic, is generated and turned into a seed.
- Length. The phrase encodes 128 to 256 bits of random data plus a short checksum. 128 bits gives 12 words, 160 bits 15, 192 bits 18, 224 bits 21 and 256 bits 24.
- Wordlist. Each word is picked from a list of 2,048 words. The standard discourages non-English wordlists, because most wallets support only English.
- Passphrase. BIP-39 allows an optional passphrase on top of the words. If none is set, an empty one is used. Every passphrase produces a valid seed, so a mistyped or forgotten passphrase opens a different, empty wallet rather than giving an error.
- One seed, many keys. Under BIP-32, a hierarchical deterministic (HD) wallet derives a whole tree of key pairs from one seed. That is why one phrase restores every account in the wallet.
Not every wallet uses BIP-39. Some software generates its own seed format, so a phrase from one wallet will not necessarily restore in another. Check which standard your wallet uses before relying on a phrase for recovery elsewhere.
Handling the seed phrase
- Paper or metal, offline. Write it down. Metal backups are built to survive fire, water and corrosion.
- No digital copies. No screenshots, photos, emails, cloud files or notes on a phone or computer. A screenshot can sync to a cloud provider without you noticing.
- More than one copy. Consider several copies kept in separate secure places.
- Enter it only into the wallet itself. On a hardware wallet, type the phrase only when the device prompts you. Never type it into a website or into software that asks for it.
- Never share it. No wallet maker, support agent or website needs it. Sharing the phrase is the same as handing over the funds.
- Plan for others. Funds can be lost for good if the people who would need access, such as family, have no way to recover them.
Common mistakes
- Screenshotting the phrase or saving it in a cloud document.
- Typing the phrase into a "support" chat, form or app after a message claims there is an error with your wallet. Legitimate staff do not contact you through private, unofficial channels.
- Using a hardware wallet that arrived pre-configured with a phrase or PIN.
- Sending to an address without checking it against the intended recipient. Transactions are irreversible.
- Skipping the test send before moving a large amount.
- Approving unlimited spending when connecting the wallet to a smart contract. An unlimited approval can let that contract drain the wallet.
- Forgetting an optional passphrase, or assuming any phrase will restore in any wallet.
- Leaving the wallet software out of date, which means missing security fixes.
This guide draws on standards documents and wallet makers' general security pages, not on any single wallet's setup screens, which differ by product.
