OrganiSation or OrganiZation – which spelling is correct?

OrganiSation or OrganiZation? The great spelling debate

Organisation or organization - which spelling?What is the correct spelling?


OrganiSation or OrganiZation – the great Atlantic debate

There is a belief that it is spelt with an ‘s’ in the UK and in the US with a ‘z’.

In fact while the US spelling is with a ‘z’ the UK preferred spelling is also with a ‘z’ and as an alternative with an ‘s’ if you follow the guidance from leading authoritative dictionaries.

This is true even in my 1972 Concise Oxford Dictionary.


Organisation or organization – So which is correct?

Both, with z being the preferred according to the dictionaries in both the US & UK. This ignores the debate that is also occurring in Canada and Australia!

Some definitions (when you search for “organisation”):
Jacket image of the Compact Oxford English Dictionary


(also organisation)

• noun 1 the action of organizing. 2 a systematic arrangement or approach. 3 an organized body of people with a particular purpose, e.g. a business.

— DERIVATIVES organizational adjective organizationally adverb.



    1. The act or process of organizing.
    2. The state or manner of being organized: a high degree of organization.
  1. Something that has been organized or made into an ordered whole.
  2. Something made up of elements with varied functions that contribute to the whole and to collective functions; an organism.
  3. A group of persons organized for a particular purpose; an association: a benevolent organization.
    1. A structure through which individuals cooperate systematically to conduct business.
    2. The administrative personnel of such a structure.

organizational or’gan·i·zation·al adj.
organizationally or’gan·i·zation·al·ly adv.

Source -” The American Heritage® Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company, 2004. 25 Mar. 2007.

organisationwebster dictionary

One entry found for organisation.

Main Entry: or·ga·ni·sa·tionor·ga·niseor·ga·nis·er

source –


There have been many debates about international spelling of organisation or organization around the world. These include the following found on a debate about computer dictionaries:


My text is marked as English (UK) but it doesn’t flag spellings like organization.

It may come as a surprise to many, but most authoritative UK English dictionaries prefer the -z- spelling for many words, and have done so for decades. English (US) only allows -z- spellings, but other countries allow -s- & -z- interchangeably except: where a particular spelling is defined for a specific entity: e.g.Commonwealth Scientific and Industrial Research Organisation.

The Macquarie Dictionary also lists -z- spellings as permissible alternates. Some institutions or texts may have stylistic preferences for one over the other.

In theory you could add all the spellings you don’t like to an exclude dictionary, but there are many thousands of such words in many forms E.G.:

Organize, organized, organizing, organizer, organizers, organization, organizations, organizational, organization’s.

Some words only have -s- forms e.g. promise, premise, chemise, compromise, merchandise, franchise, enterprise, disguise, exercise, surmise, surprise.

Organise or organize – some history

One website looks at the usage of organisation or organization and has produced this great Ngram:

Organisation or organization - which spelling is correct?

This shows that in the 1920s the Z spelling was more popular in UK publications, and yet in the 1930s this somehow changed. There was a resurgence in the 1970s, but in the early 1980s that started to drop off. It would be interesting to know the impact of microsoft word and its spell checks impact on the decision of organisation or organization from the late 1980s onwards.


There is more to it than organisation or organization

See these links for more background on the organisation or organization or  ise/ize (and yse/yze) issue:

READ  The Outstanding Organization - Book Review
About Mike Morrison

Mike Morrison is a consultant and change agent specialising in developing skills in senior people to increase organizational performance.
Mike provides training & development in senior management, leadership, change management & other strategic programs to an international client base.
Mike is also founder & director of RapidBI, an organizational effectiveness consultancy.


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  7. Hi Mike,

    Writers don’t tend to worry. What matters is setting a style and sticking to it. Consistency is the aim. As your dictionary shows, z or s is permitted spelling. The truth is that the Z is the old (pre french spelling) and that was taken to the USA by the pilgrim fathers. The s is what we were left with by the French and, by some, is preferred. It tends to be that in the UK s is the preference and I do think that it’s neater. It’s the one used by the UK based publications that I’ve written for, while US uses the Z. This follows for all words of this pattern. When in doubt, refer to the Economist Style Guide, or write your own. As I said, consistency is what matters.


  8. Hi Andrew, if only what you are saying was true – but it was that great “god” the Microsoft word spell checker that has educated us this way…

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