"Authorization" vs "Authorisation" - I'm in some real dilemma [closed]

I'm writing a professional business-related project summary, whereby half of the clientele is in the U.S while the other half of the same business is in the U.K. - and I don't want to disappoint either.

Question is - what shall I use between "Authorization" and "Authorisation" that doesn't make me look like I'm suffering from Dyslexia to one of the two sides?


Use'z'. The situation is not symmetrical.

While many people in the UK prefer the 's' (and some will make a fuss about 'z' being "American"), both forms are recognised in the UK, and the Oxford Dictionaries (which are widely taken as authorities) prefer 'z'.

On the other side, I have encountered Americans who were not even aware that 's' was a possibility, and regarded it as simply a mistake.


As shown below, authorization is the standard AmE spelling, and it used to be also the BrE standard one till the second half of the 20th century. OED, however, appears to still favour the old (zation) spelling. Ngram shows that "authorization" is still used used in BrE so I suggest you use it to address both communities.

  • For the verb meaning to grant authority or to give permission, authorize is the standard spelling in American and Canadian English. Authorise is standard in all main varieties of English outside North America.

  • The distinction extends to all derivative words. North Americans use authorized, authorizing, authorizes, and authorization, while English speakers from outside the U.S. and Canada use authorised, authorising, authorises, and authorisation.

  • Authorize is the older form, and it was standard even in British English until the second half of the 20th century. It is in the group of Classically derived words that traditionally took the -ize ending but have recently acquired -ise. The change is not wholly engrained, though.

  • The Oxford English Dictionary, which usually favors British spellings, still lists authorize as the primary spelling, and some British publishing houses also favor the old spelling. In 21st-century edited British news publications, however, authorise appears about seven times for every instance of authorize, and authorize is even less common in 21st-century Australian and New Zealand publications.

(grammarist.com)

Ngram AmE vs BrE authorization

Ngram AmE vs BrE authorisation