Bip39 Passphrase. Look at how you can securely again up and pass to the passphrase if necessary: Whilst you could possibly theoretically trust in your memory, you may want to take into account a safe backup method. No, there isn't a complex limit into the length of your respective passphrase. https://bookmark-media.com/story18857270/bip39-wallet-https-linktr-ee-bip39-bip39-generator-an-overview