Mum vs. Mom
The forms differ mainly by regional convention in the mother sense. Choose the form that matches the speaker, audience, character voice, or house style.
For the informal word meaning “mother,” “mum” is standard UK usage and “mom” is standard US usage.
Key details
Choose the right form
| Meaning / context | Use | Decision |
|---|---|---|
| UK informal mother term | mum | Use the ordinary UK form. |
| US informal mother term | mom | Use the ordinary US form. |
| quoted speech or character voice | preserve the speaker’s form | Regional voice can be part of the meaning and tone. |
Quick tests
Decision test
Are you writing the informal family word for “mother” in a clear UK or US variety?
If yes: Use “mum” for UK English and “mom” for US English.
If no: If reproducing someone’s voice or a proper name, preserve the form actually used.
Caveat: Limit the comparison to the mother sense; either spelling may appear in unrelated names, abbreviations, or other lexical contexts.
Examples
My mum is arriving this afternoon.
“Mum” is the ordinary UK informal family term.
My mom is arriving this afternoon.
“Mom” is the ordinary US informal family term.
The quotation keeps the speaker’s original use of “mum.”
Quoted voice should not be normalized without reason.
Further guidance
Core difference
Use the ordinary UK form.
Fast Test
Use “mum” for UK English and “mom” for US English. If reproducing someone’s voice or a proper name, preserve the form actually used.
Usage Boundary
Limit the comparison to the mother sense; either spelling may appear in unrelated names, abbreviations, or other lexical contexts.
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.
- mum (opens in a new tab)Cambridge University Press · Mum is UK informal for mother, with US mom identified as the counterpart.
- mom (opens in a new tab)Cambridge University Press · Mom is US informal for mother, with UK mum identified as the counterpart.