Where to keep seed phrases and secrets so heirs can find them

What counts as a secret

Not everything your heirs need is dangerous. The three layers separate the list and the instructions, which can be found by anyone without harm, from the secrets, which can’t:

• The seed phrase (usually 12 or 24 words; 20 on newer Trezors). Anyone who has it has the coins.
• The passphrase, if you use one. On its own it’s useless; together with the seed it’s everything. See Passphrases and inheritance.
• PINs and wallet passwords. Less dangerous, because a thief with only a PIN has nothing, but your heirs will want them.
• The wallet configuration file of a multisig or timelock wallet. It can’t spend anything, but without it the wallet can’t be rebuilt. Keep copies with every key.

Everything in this article is about the first two.

Paper or metal

Paper burns, fades and dissolves. A seed on paper in a drawer is fine for a few hundred euros, not for savings. For anything that matters, stamp or engrave the words into steel, or use a tile set made for it; the differences between the types are compared on multisigsetup.com. A metal plate survives a house fire. The letter of instruction that points to it needn’t: you’ll keep a copy of that elsewhere anyway.

The places, compared

Place	Survives disaster?	Private?	Heirs can reach it?
Home safe, bolted down and fire-rated	Yes, if rated for it	Burglars know what a safe is for	Yes, if they know the code or where the key is
Hidden at home, no safe	Fire: no, unless metal	Only until the house is cleared	Only if the letter says exactly where
Bank safe deposit box	Yes	Yes	Not for a while. See below
Private vault company	Yes	Yes	Depends on their rules; usually a notary or probate document
Sealed envelope with your lawyer or notary	Depends on their office	Yes	Yes, through the estate
Sealed envelope with a relative or friend	Depends on their house	As private as the person	Yes, if they’re still reachable
Password manager, cloud note, email, photo	Survives, and gets copied	No	Yes, and so can anyone who gets into the account

Nothing in the last row is acceptable for a seed phrase, however convenient. An encrypted note can’t be inherited without its password, and an unencrypted one is a gift to whoever phishes you first.

The safe deposit box problem

A bank box is secure, which is exactly the problem after a death. Banks block everything in the name of someone who has died until they see proof of who may act for the estate, and the box is no exception.

• United States. Rules differ per state, but the default is that the box stays closed until the executor shows the court’s appointment papers. Some states let a relative open it earlier, with a bank officer watching, to look for a few documents only: the will, burial instructions or an insurance policy. Texas spells it out: a spouse, parent, adult descendant or named executor may examine the box in the bank’s presence, and only those documents may be taken out (Texas Estates Code, chapter 151). California lets anyone holding a key open the box with proof of death and ID, but only to take burial instructions and copies of a will or trust; the person “shall not remove any of the contents” beyond that (Probate Code §331). A seed phrase isn’t on any of these lists. Pennsylvania goes further and requires a bank-witnessed inventory of the box for inheritance tax before anything other than the will or burial instructions leaves it (61 Pa. Code §93.31).
• United Kingdom. Metro Bank, one of the few high-street banks still renting boxes, says the contents are released to the beneficiary or executor “once we have received their Grant of Probate or Letters of Administration”, and that any joint or named visitor’s access ends when the holder dies (Metro Bank). Probate takes months.
• Netherlands. Banks block all access on notice of death and ask for a verklaring van erfrecht from a notary before anything is handed over (ABN AMRO). Private vault companies work the same way through a notary (De Nederlandse Kluis).

So a box is a good place for a copy of the seed, never the only one. A box in joint names helps at some providers and not at others; read the contract. And tell your executor the box exists: in the US, the estate tax return asks about it.

Splitting a seed

The instinct is to write half the words in one place and half in another. Don’t: each half makes the rest easy to brute-force, and losing either half loses everything. If you want a backup in parts, use a scheme designed for it:

• SLIP39 (Shamir backup). The seed is split into shares, of which you choose how many are needed, say three of five. Two shares alone reveal nothing. Trezor devices (Safe 3, Safe 5, Safe 7 and Model T) create and restore these (Trezor), and the Keystone 3 Pro can too (Keystone); Ledger, BitBox02 and Coldcard can’t restore SLIP39 shares (Coldcard has its own Shamir format, Codex32, which isn’t compatible). Your heirs will need a compatible device, so write that down.
• Seed XOR (Coldcard) splits a seed into parts that all have to be present. Good against theft, bad against loss.
• Multisig is the other route: three separate seeds, any two of which suffice, so no single place holds the coins. Where to put those three is its own question, answered on multisigsetup.com.

A pattern that works for most people

1. The seed on metal in a fire-rated safe at home, or hidden well if you don’t have a safe.
2. A second copy of the seed somewhere else: a bank box, a vault, your lawyer, a relative in another town.
3. If you use a passphrase, it lives apart from both seed copies, with someone or somewhere different.
4. The letter of instruction says where each of these is, in words a stranger couldn’t act on but your executor can: “the steel plate is in the safe in the study; the code is with our solicitor”.
5. Once a year, check that each place still exists, the plate is still readable and the people are still reachable: the yearly check-up.

Next: Passphrases and inheritance.