Writing & StyleStyle guide

B vs. Bn for Billion

There is no single universal abbreviation for “billion.” Government of Canada guidance documents “B” but warns against it in formal writing, while the University of Reading uses “bn” in its money style and Microsoft product displays use “B” for compact numbers. The governing house style should decide.

Quick answer

“B” and “bn” both occur, but they are style-dependent; spell out “billion” when clarity or formal prose matters and no house style specifies an abbreviation.

Key details

Core IssueB and bn are both used for billion in different editorial and display systems; neither should be presented as a universal English standard.
Phrase Rolelarge-number-abbreviation
Registerbusiness, financial, and display writing

Important caveats

Usage Boundary

Use the abbreviation specified by the publication, product, or financial style; otherwise writing “billion” in full is usually clearer.

Further guidance

B Form

“B” is used in some compact or journalistic/display contexts, but at least one government writing reference advises against it in formal prose.

Bn Form

“bn” is an explicit house-style abbreviation for billion in some institutional money formatting.

Sources and evidence

Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.

  1. billion, B (billion) — Writing Tips Plus (opens in a new tab)Government of Canada Language Portal · Use and formality boundary for B as an abbreviation for billion
  2. University of Reading house style — abbreviations for money (opens in a new tab)University of Reading · House-style use of m, bn, and tn for money figures
  3. Configure display column properties — large-number abbreviations (opens in a new tab)Microsoft Learn · Product-interface examples using B and T for compact large-number display

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