What does self-custody mean in Bitcoin?

Self-custody means your private keys live on your device, not on a company's server. You control your Bitcoin directly. No one can freeze it, move it, or lose it for you. No one can recover it for you either.

What is the difference between a custodial and non-custodial wallet?

A custodial wallet (like an exchange account) holds your keys for you. You see a balance, but the exchange controls the Bitcoin. A non-custodial wallet puts the keys on your device. You move the Bitcoin yourself, and no one else can.

Is self-custody safe?

It removes the risk of an exchange losing your Bitcoin through hacks, freezes, or insolvency. It adds the risk of losing your own keys. Passkey-based wallets reduce that risk by syncing key material across your devices automatically through iCloud or Google.

Do I need a hardware wallet for self-custody?

No. A hardware wallet is one option. A phone-based wallet that derives keys from a passkey is also self-custody. Piggy does this: your keys are derived on your device from a passkey using the WebAuthn PRF extension. The device form factor does not change the custody model.

Can I switch from an exchange to a self-custody wallet?

Yes. Withdraw Bitcoin from the exchange to your wallet's Lightning address or onchain address. Once confirmed, the exchange no longer holds it. With Lightning, the transfer is instant and the fee is less than one sat.

What happens if I lose my phone?

With a passkey wallet like Piggy, your passkey syncs through iCloud Keychain or Google Password Manager. Sign in on a new phone and the same keys are re-derived. If you also exported a seed phrase, that works too. If you lose both your device provider account and your backup, the Bitcoin is gone.

What Is a Self-Custody Bitcoin Wallet?

Your Bitcoin is controlled by a private key. Whoever holds that key can move the funds. In a self-custody wallet, the key lives on your device. The company that made the wallet never sees it, never stores it, and cannot use it. If they shut down tomorrow, your Bitcoin is still there.

Most people who own Bitcoin do not have self-custody. They have an account on an exchange, which is closer to an IOU. The exchange holds the keys. You hold a login.

What the exchange actually holds

When you buy Bitcoin on Coinbase or Binance, the exchange creates a balance entry in its database. Your Bitcoin sits in the exchange's wallets, mixed with everyone else's. You can see the number in your account, but you cannot point to specific sats that are yours on the blockchain. You are trusting the exchange to keep track, stay solvent, and let you withdraw when you want to.

This is the same model as a bank. It works most of the time. But Bitcoin was built so you would not need to trust an institution with your money, and an exchange account gives that back.

FTX collapsed in November 2022. Customers had balances on screen. The Bitcoin was gone. Mt. Gox collapsed in 2014. Same story. These are not edge cases from early crypto. FTX was the second-largest exchange in the world.

What self-custody changes

A self-custody wallet derives a private key on your device. That key controls specific sats on the blockchain. When you want to move them, the wallet signs a transaction with your key. No one approves it. No compliance review. No withdrawal limit. The blockchain sees a valid signature and the sats move.

The wallet app itself is an interface. It shows your balance, builds transactions, and talks to the network. But the key is the thing that matters, and the key is on your device. If the wallet company disappears, you can take your key to another app and your sats are still there.

Older wallets generate a 12 or 24 word seed phrase and derive the key from it. You write the words on paper and hope you do not lose the paper. Newer wallets like Piggy use passkeys. Your phone's authenticator holds the key material and your device provider (Apple or Google) syncs it automatically. No paper. No words to misplace. Same custody model underneath.

What you are responsible for

If you lose access to your private key and have no backup, the Bitcoin is permanently gone. There is no customer support for this. There is no recovery flow. The blockchain does not know who you are and does not care.

This is the tradeoff people talk about when they talk about self-custody. You get full control. You also get full consequences.

How much this scares you depends on the backup method. A seed phrase on a piece of paper is easy to lose, easy to photograph by accident, and most people store it badly. A passkey synced through iCloud Keychain or Google Password Manager is much harder to lose. Your phone breaks, you sign in on a new one, the passkey comes with you, and the wallet re-derives the same keys. Piggy also lets you optionally export a seed phrase as a second backup if you want both.

When it matters

For Bitcoin you plan to stack over time and leave alone, self-custody is the setup where you actually own what you are saving. An exchange balance is a claim on someone else's system. A self-custody wallet is your key, your sats, on the blockchain.

Piggy is built for this specific use. You feed it sats, it holds them, and if you ever empty it, it dies permanently. The death mechanic exists because Piggy is a savings wallet, not a spending wallet. The sats are meant to stay.

For trading, most people keep Bitcoin on exchanges because the Bitcoin needs to be there to trade. The usual approach: buy on an exchange, withdraw to self-custody for storage.

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