Why steel seed plates only give you room for four letters per word

A lot of people wonder why a plate for writing down your words only has room for four letters per word.

The 24 words that every make of device — Ledger, Trezor, KeepKey, Digital Bitbox, SafePal or SecuX — picks at random come from BIP39.

None of those words shares the same first four letters with any other. For example:

• add
• addict
• address

You will notice the fourth letter is never the same, which means we only need to write down four letters.