Bitcoin's superpower — nobody can take it without your keys — has a grim flip side: nobody can recover it without your keys, including your family. Chain-analysis estimates suggest millions of coins are already permanently stranded, and some fraction belonged to people who died without a plan. The fix doesn't require lawyers or complex tooling; it requires an evening.
Step 1: write the letter. A physical document explaining, in plain language a non-technical spouse could follow under stress: what you own (coins exist, roughly where), where the seed phrase backup lives, what a hardware wallet is and where yours is, and a warning list — no legitimate person will ever call asking for the seed phrase; beware "recovery services." Don't include the seed phrase itself in the letter.
Step 2: separate knowledge from access. The letter says where things are; the seed phrase backup is the access. Keep them in different places — letter with your will or important documents, seed backup in a safe or bank deposit box. A thief finding one shouldn't have everything, but your heir following the letter should be able to reach both.
Step 3: tell exactly one or two people. Someone you deeply trust needs to know the letter exists and where it is — that's it. They don't need amounts, they don't need the phrase, they need a pointer. This is the narrow exception to the don't-advertise-your-holdings rule.
Step 4: rehearse and revisit. Once a year: confirm the seed backup is where the letter says, the letter reflects your current setup, and your trusted person still remembers the pointer. Wallets get migrated and safes get moved; an outdated letter fails exactly when it's needed.
Exchange-held coins are the easier case — regulated platforms have deceased-estate processes that work through normal probate with a death certificate. That convenience is real, and so is the trade-off: it's the custody compromise covered in our wallet guide. Whichever mix you hold, the test is simple: if you vanished tomorrow, could your family find the letter, and would it actually work? If yes, you've done more than most of the industry.