What does authorisation mean?
"Authorisation" is the British English noun denoting official permission granted by someone with the power to give it — whether a government body, employer, bank, or other authority. It covers both the act of granting permission ("the authorisation of new spending") and the formal document that records it ("carrying a signed authorisation"). The word sits in a formal register, appearing frequently in legal, financial, medical, and administrative contexts: transactions require authorisation, procedures require authorisation, access requires authorisation. Its American counterpart is spelled "authorization," with no difference in meaning. Because it implies a legitimate authority standing behind the permission, the word conveys legitimacy and procedure rather than casual consent — you might ask a friend's forgiveness, but you seek authorisation from a superior. It derives ultimately from the Latin "auctor," meaning originator or promoter, the same root that gives us "author" and "authority."
Official permission granted by an authority for a particular action or purpose.
"The project cannot proceed without authorisation from the board."
Uncountable when referring to the act of granting permission.
A formal document or certificate that grants such permission.
"He presented a written authorisation allowing him to collect the parcel on her behalf."
Countable in this sense; can take a plural form.
Used only in the countable sense of individual documents or instances of permission being granted.
"All authorisations must be filed with the compliance office before the audit."
That sneaky '-isation' ending marks this as a French import — Americans trimmed it down to 'authorization' in the early 1800s, but Britain never got the memo.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of authorisation
Authorisation entered English in the late 18th century via the verb "authorise," which came from Old French "autoriser" (modern French "autoriser"), itself derived from Latin "auctorizare" — to give authority to. All of these trace back to the Latin noun "auctor," meaning originator, promoter, or creator, the same root behind "authority" and "author." The British spelling with "-is-" reflects the French-derived suffix, while American English later standardized on the Greek-influenced "-ization" spelling. Cognates appear across Romance languages, including French "autorisation" and Spanish "autorización."
Related word forms
How authorisation is actually used
"Authorisation" is the standard British spelling; American English uses "authorization." The word carries a formal, bureaucratic register — it appears most often in legal, corporate, medical, and governmental contexts. In everyday speech people often prefer simpler words like "permission" or the informal "the go-ahead," so using "authorisation" signals formality. It is typically uncountable when referring to the act of permitting ("you need authorisation") and countable when referring to a document ("a written authorisation").
Easily confused with authorisation
"Authorization" is the standard American spelling, while "authorisation" is the British spelling — the words mean exactly the same thing.