Traditional assets seamlessly transfer through legal probate courts upon death. Decentralized assets do not care about court orders. If your family does not have your private keys, they do not have your crypto. Period.
The 'Letter of Instruction'
Leaving a seed phrase in a safe is useless if your spouse or children don't know what a seed phrase is. Your estate plan must include a step-by-step 'Letter of Instruction' detailing exactly how to download a wallet, restore the phrase, and transfer the assets to an exchange to cash out.
Crucially, do not put your seed phrase in your legal Last Will and Testament, as wills eventually become public record, making your funds instantly stealable.
Dead Man's Switches and Multi-Sig
Advanced setups involve using Multi-Sig wallets where an estate lawyer holds one key, your spouse holds another, and a third is held in a safety deposit box. Even if the lawyer goes rogue, they cannot steal the funds with only one key.
Similarly, smart contract 'Dead Man's Switches' can be programmed to automatically transfer funds to a designated wallet address if you fail to 'check in' with a transaction after 12 months.