There are lots of British-American spelling lists on the internet, but most of them are low-quality references. That's why I created this spelling guide as a reliable reference for editors interested in British and American spellings. The lists are quite exhaustive. Acceptable variants (according to Merriam-Webster and the Concise Oxford English Dictionary) are given in parentheses. See also American and British English spelling differences.
Key examples of the most important differences about which you should know:
labour (UK) <-> labor (US)
- Details: see -our, -or
centre (UK) <-> center (US)
- Details: see -re, -er
travelling (UK) <-> traveling (OR travelling) (US)
- Details: see -ll-, -l-
fulfil (UK) <-> fulfill (OR fulfil) (US)
- Details: see -l-, -ll-
dialogue (UK) <-> dialogue (OR dialog) (US)
- Details: see -logue, -log
organise (OR organize) (UK) <-> organize (US)
- Details: see -ise, -ize
analyse (UK) <-> analyze (US)
- Details: see -yse, -yze
defence (UK) <-> defense (US)
- Details: see -ce, -se
anaesthesia (UK) <-> anesthesia (US)
- Details: see -oe-/-ae-, -e-
tyre, aluminium, apprenticeship programme (UK) <-> tire, aluminum, internship program (US)
- Details: see Other
UK US arbour arbor ardour ardor armour armor armoury armory behaviour behavior behavioural behavioral behaviourism behaviorism belabour belabor candour candor clamour clamor colour color coloration (OR colouration) coloration demeanour demeanor dolourous dolorous enamour enamor endeavour endeavor favour favor favourable favorable favourite favorite favouritism favoritism fervour fervor flavour flavor glamour glamour (OR glamor) 'glamour' is preferred harbour harbor in US English honour honor honourable honorable 'glamorous', 'honorific' humour humor 'honorary' and 'humorous' in labour labor British and American English! misdemeanour misdemeanor neighbour neighbor odour odor parlour parlor rancour rancor rigour rigor 'rigorous'! rumour rumor saviour savior savour savor splendour splendor succour succor tumour tumor tambourine tamborine ? valour valor vapour vapor vigour vigor CANADIAN usage: -our as in UK English (colour, favour, honour)
UK US calibre caliber (OR calibre) centilitre centiliter centimetre centimeter centre center centred centered centring centering decilitre deciliter decimetre decimeter epicentre epicenter fibre fiber (OR fibre) goitre goiter kilometre kilometer lacklustre lackluster litre liter lustre luster meagre meager (OR meagre) meter (device) meter (device) metre (unit of length) meter (unit of length) micrometre micrometer millilitre milliliter millimetre millimeter mitre miter (OR mitre) mitred mitered (OR mitred) philtre philter (OR philtre) reconnoitre reconnoiter (OR reconnoitre) reconnoitred reconnoitered (OR reconnoitred) reconnoitring reconnoitering (OR reconnoitring) sabre saber (OR sabre) saltpetre saltpeter sceptre scepter sceptred sceptered sepulchre sepulchre (OR sepulcher) spectre specter (OR spectre) theatre theater (OR theatre) 'theatre' is very common in US English CANADIAN usage: -re, as in UK English (centre, fibre, kilometre)
UK US cancellation cancellation (OR cancelation) Spellings like travelling, cancelled canceled (OR cancelled) labelled, modelling are cancelling canceling (OR cancelling) not very common, but counsellor counselor (OR counsellor) acceptable in US English equalled equaled (OR equalled) equalling equaling (OR equalling) dialler (OR dialer) dialer dialling dialing (OR dialling) fuelled fueled (OR fuelled) fuelling fueling (OR fuelling) labelled labeled (OR labelled) labelling labeling (OR labelling) marvellous marvelous (OR marvellous) modelled modeled (OR modelled) modelling modeling (OR modelling) quarrelled quarreled (OR quarrelled) quarrelling quarreling (OR quarrelling) signalled signaled (OR signalled) signalling signaling (OR signalling) tranquillity (OR tranquility) tranquillity (OR tranquility) travelled traveled (OR travelled) travelling traveling (OR travelling) woollen woolen (OR woollen) CANADIAN usage: -ll-, as in UK English (counsellor, labelled, travelling)
UK US enrol enroll (OR enrol) Spellings like fulfilment and enrol enrolment enrollment are not very common, but acceptable fulfil fulfill (OR fulfil) in US English fulfilment fulfillment (OR fulfilment) install (OR instal) install (OR instal) instalment installment (OR instalment) skilful skillful wilful willful (OR wilful)
UK US analogue analogue (OR analog) catalogue catalog (OR catalogue) 'catalogue' is also common dialogue dialogue (OR dialog) in U.S. English monologue monologue (OR monolog) prologue prologue (OR prolog) 'analog' and 'dialog' are sometimes travelogue travelogue (OR travelog) found in British English sources, but only in a technical context
Important: Both -ise and -ize can be used in UK English. Contrary to widespread belief, -ize is NOT an Americanism. Read more...
UK US apologise (OR apologize) apologize emphasise (OR emphasize) emphasize In UK English, -ise spellings colonise (OR colonize) colonize are more common. globalisation (OR globalization) globalization maximise (OR maximize) maximize The OED prefers -ize. organisation (OR organization) organization privatisation (OR privatization) privatization realise (OR realize) realize recognise (OR recognize) recognize recognisable (OR recognizable) recognizable standardise (OR standardize) standardize . . . . . . -ise (OR -ize) -ize The following words always end in -ise: advertise, advise, apprise, arise, chastise, circumcise, comprise, compromise, demise, despise, devise, disguise, enfranchise, enterprise, excise, exercise, franchise, improvise, incise, merchandise, premise, revise, supervise, surmise, surprise, televise... CANADIAN usage: generally -ize instead of -ise.
The -yse/-yze ending is a different case! In UK English, the ending is always -yse. In US English, the ending is always -yze.
UK US analyse analyze analysing analyzing breathalyser breathalyzer catalyse catalyze catalysing catalyzing dialyser dialyzer hydrolyse hydrolyze hydrolysing hydrolyzing paralyse paralyze paralysing paralyzing photolyse photolyze photolysing photolyzing CANADIAN usage: -yze is preferred
UK US defence defense licence (noun) license (OR licence) (noun) 'to licence' is wrong. license (verb) license (verb) offence offense practice (noun) practice (noun) practise (verb) practice (OR practise) (verb) pretence pretense (OR pretence)
UK US aeon (OR eon) aeon (OR eon) aesthetic aesthetic (OR esthetic) amoeba amoeba (OR ameba) anaemia anemia anaesthesia anesthesia archaeology archaeology (OR archeology) caesium cesium diarrhoea diarrhea encyclopedia (OR encyclopaedia) encyclopedia faeces feces (OR faeces) foetus (OR fetus) fetus According to the Concise Oxford English gonorrhoea gonorrhea Dictionary, "fetus" is an acceptable gynaecology gynecology variant in British English, especially haemoglobin hemoglobin in technical use. haemophilia hemophilia UK medical journals prefer "fetus". haemorrhage hemorrhage homeopathy (OR homoeopathy) homeopathy ischaemic ischemic leukaemia leukemia manoeuvre maneuver manoeuvring maneuvering medieval (OR mediaeval) medieval (OR mediaeval) oedema edema oenology oenology (OR enology) oesophagus esophagus oestrogen estrogen orthopaedic orthopedic paediatrics pediatrics paedophile pedophile palaeontology paleontology
UK US ageing (OR aging) aging (OR ageing) preferred international (IUPAC) aluminium aluminum spelling is 'aluminium' carburettor (OR carburetter) carburetor cheque (only noun!) check 'to check' and 'to curb'! dreamt (OR dreamed) dreamed (OR dreamt) grey gray (OR grey) 'grey' is very common kerb (only noun!) curb in US English leapt (OR leaped) leaped (OR leapt) learnt (OR learned) learned maths math mould mold (OR mould) mouldering moldering moulding molding mouldy moldy (OR mouldy) moult molt moustache mustache (OR moustache) mum mom programme (but: computer program) program UK English: training programme, pyjamas pajamas television programme, research programme sceptical skeptical spelt (OR spelled) spelled storey (a storey of a building) story storeyed storied sulphur sulfur (OR sulphur) preferred international (IUPAC) tyre (as in "car tyre") tire spelling is 'sulfur'
- US and UK English spelling: see lists above. Standard reference for UK English spelling: OED, for US English spelling: Merriam-Webster.
- Irish English spelling is virtually identical to UK English spelling.
- Australian English spelling is very close to UK English spelling. The standard reference for Australian English spelling: Macquarie Dictionary. -> labour, centre, travelling, fulfil, dialogue, analyse, defence, tyre, aluminium, training programme/program. However, note that the Australian Labor Party uses the American spelling of its name due to an American influence in the early days of the party and distinguish it from the labour movement. While -ise and -ize, and -yse and -yze might be interchangeable in UK English, -ise and -yse are standardised in Australian English. Some of Australia's media publications have flirted with some American spelling norms until around 2007, but have since reverted to the UK English spelling norms after widespread complaints from its readers.
- New Zealand English spelling is very close to UK English spelling.
- Canadian English spelling uses both UK and US English spellings. In Canadian English -ize and -yze are preferred to -ise and -yse. The standard reference for Canadian English spelling is the Canadian Oxford Dictionary. -> labour, centre, travelling, fulfill, dialogue, analyze, defence, tire, aluminum, training program
Proper names should retain their original spellings. Examples:
- Rockefeller Center
- Australian Defence Force
- World Trade Organization
- North Atlantic Treaty Organisation
- International Labour Organization
- International Centre for Settlement of Investment Disputes
- World Food Programme
- International Color Consortium
- Pearl Harbor
- Victoria Harbour
Oxford Dictionaries - Robust Oxford Dictionary of British/American English and other Languages
Cambridge Dictionaries Online
Merriam-Webster Online Dictionary
Macquarie Dictionary - Australia's National Dictionary Online Most UK to US Spellings(Above 1700links)Media:http://www.tysto.com/articles05/q1/20050324uk-us.shtmlMedia:http://www2.gsu.edu/~wwwesl/egw/jones/differences.htmMedia:http://www.musicalenglishlessons.org/spelling-diffs.htm