---
title: "BIP39 Word #1237: once — Seed Phrase Mnemonic Word"
url: "https://bip39-phrase.com/bip39-word/once/"
language: "en"
updated: "2026-10-19T00:00:00+00:00"
---

Word #1237 10011010100 

# once — BIP39 word #1237

"**once**" is word #1237 of the 2048 words in the official BIP39 English wordlist, between [omit](/bip39-word/omit/) and [one](/bip39-word/one/). In a seed phrase it stands for the 11-bit value `10011010100`, decimal index 1236\. 

/wʌns/  · _adverb:_ one time only, or at some time in the past 

[Russian](/ru/ "The BIP39 wordlist with Russian translations"): однажды 

## Binary Representation

Five 1-bits and six 0-bits; 462 of the 2048 indexes have exactly five 1-bits.

One wrong bit turns it into (leftmost bit first):

[box](/bip39-word/box/)[surround](/bip39-word/surround/)[ritual](/bip39-word/ritual/)[melody](/bip39-word/melody/)[myth](/bip39-word/myth/)[ozone](/bip39-word/ozone/)[obtain](/bip39-word/obtain/)[oppose](/bip39-word/oppose/)[old](/bip39-word/old/)[onion](/bip39-word/onion/)[one](/bip39-word/one/) 

Position

Hex Index

0x4D4

4-Letter Prefix

once

## About "once" in BIP39

- "once" has 4 letters, but the first three, **"onc"**, already identify it, because **"on"** also begins [one](/bip39-word/one/), [onion](/bip39-word/onion/), [online](/bip39-word/online/) and [only](/bip39-word/only/). Three letters are enough for only 604 of the 2048 words.

## Word #1237 in the Other 9 BIP39 Wordlists

[Czech](/czech/) pluk 

[French](/french/) mesure 

[Italian](/italian/) pasticca 

[Japanese](/japanese/) つねづね 

[Korean](/korean/) 외삼촌 

[Portuguese](/portuguese/) masmorra 

[Spanish](/spanish/) niebla 

[Traditional Chinese](/chinese-traditional/) 耳 

[Simplified Chinese](/chinese-simplified/) 耳 

## Similar Words — Check Carefully During Recovery

 One BIP39 word differs from "once" by just a single letter — the most common source of typos when a seed phrase is entered by hand: 

[one](/bip39-word/one/) 

## More BIP39 Words Starting with "O"

[ #1233 old ](/bip39-word/old/)[ #1234 olive ](/bip39-word/olive/)[ #1235 olympic ](/bip39-word/olympic/)[ #1236 omit ](/bip39-word/omit/)[ #1238 one ](/bip39-word/one/)[ #1239 onion ](/bip39-word/onion/)[ #1240 online ](/bip39-word/online/)[ #1241 only ](/bip39-word/only/) 

[View all words starting with "O" ](/bip39-words/o/) 

## Seed phrase, key and recovery guides

- [How to Store a Seed Phrase: Paper, Steel and Safe Locations](/store-a-seed-phrase/)
- [How to Restore a Wallet From a Seed Phrase: Step by Step](/restore-wallet-from-seed-phrase/)
- [xpub, ypub and zpub: Extended Public Keys Explained](/xpub-ypub-zpub/)

[ Full BIP39 Wordlist ](/)