What is a seed phrase?

A seed phrase is a list of 12 or 24 ordinary words that a crypto wallet gives you when you first set it up. The words are a backup of the whole wallet. Typed into a new device in the right order, they restore every key and every balance.

How does a seed phrase work?

A crypto wallet controls funds through private keys, long secret numbers that authorize spending. Modern wallets do not create each key separately. They generate one large random number, called the seed, and derive all of their keys from it by a fixed formula.

The seed phrase is that random number written in a form people can copy down. Under a standard introduced in 2013 and known as BIP39, the number is converted into words drawn from a fixed list of 2,048. The same words in the same order always produce the same keys. It is also called a recovery phrase or a mnemonic.

In a self-custody wallet, no company has a copy of the phrase, and there is no way to reset it.

How do people store a seed phrase?

The aim is to keep the words away from anything connected to the internet while making sure they survive accidents. Wallet makers and security researchers generally describe the same practices:

• Writing the words on paper, or stamping them into a metal plate that resists fire and water.
• Keeping the copy somewhere private and secure, sometimes with a second copy in a separate location.
• Never photographing the words, or saving them in email, notes apps, cloud storage or a form on a website.

Each choice trades one risk for another. More copies protect against loss but give a thief more chances. A single well-hidden copy can be destroyed, or never found by heirs.

Why do scammers want it?

The seed phrase is the single most valuable thing a thief can obtain. With it, they can rebuild the wallet on their own device anywhere in the world and empty it, without the victim's phone, password or hardware wallet.

Most schemes are built to get the owner to type the words somewhere. Common versions include fake wallet apps, phishing sites that say a wallet must be "verified" or "synced," and impostors posing as support staff, one of the most common crypto scams.

The pattern is consistent. A legitimate wallet asks for the phrase only when the owner is restoring a wallet on a device in their own hands. No real company, exchange or government agency asks for it by message, phone or web form.

What if it is lost?

Losing the phrase is harmless while the original device still works, and serious once it does not. The guide to losing a seed phrase or private key explains what can and cannot be recovered.