You hold the seed phrase
Blitz does not store your 12-word backup. Anyone who gets the words may be able to control the wallet.
What self-custody means
A self-custody Bitcoin wallet means you hold the keys. Not a bank, not an exchange, not Blitz. Your 12-word seed phrase is the backup that lets you recover the wallet.
The basics
What self-custody means
Think of a safe you own. Only your key opens it. Blitz helps you use it, but cannot open it for you.
Operators help process transfers
Spark operators participate in ordinary Spark state changes. If they are unavailable or do not cooperate, normal Spark transfers can be delayed or stop.
Recovery has requirements
If Spark operators go offline, Spark’s unilateral exit lets you withdraw to Bitcoin without them, though today it’s a technical process that isn’t built into Blitz. Our security page explains the steps and limits.
Custodial vs self-custodial
How they compare
| Question | Custodial service (varies) | Blitz |
|---|---|---|
| Who holds the keys? | The service provider | You control the seed phrase; Spark operators participate in state changes |
| Who participates in normal transfers? | The service provider | Spark operators participate |
| Can you exit without the provider? | Depends on the wallet | Through Spark’s unilateral exit |
| If you lose backup? | Reset password | Key access may be lost; Spark recovery is a separate process |
| Privacy | Account information varies by provider | No ID is required to create a Blitz wallet |
How to do it right
How to back up your wallet
Write it on paper
Copy the 12 words in order by hand and double check them. Keep the backup in a secure place.
Never share or screenshot
Anyone with the words can take the funds. Do not email, save to the cloud, or share them. Blitz will never ask for them.
Test your recovery
After backing up, try restoring on another device, then wipe it. If it works once, it will work when you need it.
Add a PIN & biometrics
Blitz lets you lock the app with PIN, Face ID or fingerprint. Your wallet secret stays encrypted on device.
FAQ
Common questions
Can Blitz help if I lose my backup?
Blitz cannot retrieve your seed phrase. If you lose it and have no other copy, you will lose access to the wallet. Keep the words private and backed up.
Is self-custody harder to use?
Blitz is designed to make day-to-day payments simple, but you are responsible for keeping your seed phrase safe.
What about large amounts?
Blitz is designed for day-to-day use. Before keeping a large balance in any wallet, understand its payment and recovery model and choose a setup that fits your needs.