“Organize” and “organise” are not a simple one-form-per-country pair. Cambridge lists “organize” as its headword and notes “UK also organise,” so British usage allows both forms.
ReviewedEvidence1 sourceSectionEnglish Usage
Quick answer
Both spellings occur in British English, while “organize” is the normal US spelling; follow the required dictionary or house style.
Key details
Confusion Familyregional-spelling
Rule Familyregional-orthography
Termsorganize, organise
Variant ScopeUS normally organize; UK organize and organise are both documented.
Further guidance
Core difference
Cambridge explicitly notes “UK also organise” under “organize.”
Fast Test
Match the spelling to the regional or house style required by the document, then keep that choice consistent.
Variant Boundary
Do not claim that “organize” is exclusively American; British English also uses -ize in established styles.
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.
“Aging” and “ageing” are established regional spellings. Cambridge labels aging as US and ageing as UK, so the choice should follow the intended variety or house style.
“Analyze” is the standard US spelling and “analyse” is the standard UK spelling of the same verb. The distinction is regional spelling; use the form that matches the target variety or editorial style.
“Behavior” is the US spelling and “behaviour” is the UK spelling. Use the form consistent with the regional variety or editorial style of the document.
Both “canceled” and “cancelled” are standard past-tense spellings of “cancel”; US English usually uses one l, while UK English normally uses two. Cambridge records the -ll- forms and notes that US English usually uses -l-, so the difference should be presented as a regional preference rather than a correctness split.
