Seed phrases and backups

A seed phrase, also called a recovery phrase, is a list of 12 or 24 ordinary words that a wallet shows you once, when you create it. Those words can recreate every key in the wallet on any compatible app or device. Whoever has them has the bitcoin.

Why the words matter so much

The words are picked at random from a fixed list of 2,048. Behind them is a number so large that guessing it is not possible in practice. That is what protects you, and it is also why there is no "forgot password" button: no company keeps a copy, so nobody can reset it for you.

Lose the phone, keep the words	Install a wallet on a new device, type the words, and everything comes back.
Lose the words, keep the phone	Everything still works. Write down a new backup at once, or move the coins to a fresh wallet with new words.
Lose both	The bitcoin can't be moved by anyone, ever. This is one of the main ways coins are lost.
Someone else sees them	They can take everything from anywhere in the world, and the payment can't be undone.

How people usually store them

• Written on paper or stamped into metal, never typed into a computer, a website or a chat.
• Not photographed, and not saved in notes, email or cloud storage, where a hacked account exposes them.
• Kept somewhere protected from fire, water and curious visitors. Some people keep a second copy in another place.
• Checked once: some wallets let you test the words before you rely on them.

Some wallets also offer an extra password, sometimes called a passphrase, that is added to the words. It adds protection, and one more thing that can be forgotten.

Restoring a wallet from the words

Install a wallet app from its maker's own site, or use the hardware device, and choose the option to restore or import an existing wallet, never to create a new one. Type the words in their exact order. If you set an extra passphrase, enter that too. If the balance shows as zero, the coins usually aren't gone: many wallets let you choose which kind of address to look for, such as ones starting with 1, 3 or bc1, and the right setting brings them back. Never type the words into a website or send them to anyone who offers to restore the wallet for you.

The rule that stops the most theft

Nobody legitimate ever needs your seed phrase: not a wallet maker, not an exchange, not a support agent, not a website that says it will "sync" or "validate" your wallet. Every request for it is someone trying to take your bitcoin. More in fake apps, fake support.