The lists below give the most common spelling differences between British and US English. As stated above, most but not all of these will be picked up by your computer spell checker. However, it is important to be familiar with the basic spelling differences between the two varieties.

As already mentioned, generally speaking British spellings are also used in Ireland, Australia, New Zealand and South Africa. The US column gives spellings used in the United States. Canadian English uses features of both British and US English, depending on the type of text.

-ou- and -o-

British English US English
arbour some meanings arbor
ardour ardor
armour armor
behaviour behavior
candour candor
clamour clamor
colour color
demeanour demeanor
enamour enamor
endeavour endeavor
favour favor
fervour fervor
flavour flavor
glamour glamour or glamor
harbour harbor
honour honor
humour humor
labour labor
mould mold
moult molt
neighbour neighbor
odour odor
parlour parlor
rancour rancor
rigour some meanings rigor
rumour rumor
saviour savior or saviour
savour savor
smoulder smolder or smoulder
splendour splendor
succour succor
tumour tumor
valour valor
vapour vapor
vigour vigor

-ae- and -e-

British English US English
aesthetic aesthetic also esthetic
anaemia anemia
anaesthesia anesthesia
archaeology archaeology or archeology
Caesarean section cesarean section
caesium cesium
faeces also feces feces
gynaecology gynecology
haematology hematology
hypoglycaemia hypoglycemia
leukaemia leukemia
orthopaedic orthopedic
paediatrics pediatrics
Palaeolithic Paleolithic
palaeobiology etc. paleobiology etc.

-oe- and -e-

British English US English
amoeba ameba or amoeba
apnoea apnea
coeliac celiac
diarrhoea diarrhea
gonorrhoea gonorrhea
manoeuvre maneuver
oesophagus esophagus
oestrogen estrogen

-ph- and -f-

British English US English
sulphur sulfur
sulphate sulfate
sulphite sulfite
sulphuric sulfuric

-pp- and -p-

British English US English
worshipping worshiping or worshipping
worshipped worshiped or worshipped
worshipper worshiper or worshipper

-ll- and -l-

These differences include verb forms with -ing and -ed, but not the to form. However, neither British nor US English is consistent – for instance, equally and equality in both – so always use a spell checker or dictionary as your guide. A number of examples are given below:

British English US English
bevelling beveling
bevelled beveled
cancelling canceling
cancelled canceled
cancellation cancellation or cancelation
counselling counseling
counselled counseled
counsellor counselor
dialling dialing
dialled dialed
duelling dueling
duelled dueled
duellist duelist
equalling equaling
equalled equaled
fuelling fueling
fuelled fueled
jeweller jeweler
jewellery jewelry
labelling labeling
labelled labeled
levelling leveling
levelled leveled
libelling libeling
libelled libeled
libellous libelous
marshalling marshaling
marshalled marshaled
modelling modeling
modelled modeled
quarrelling quarreling
quarrelled quarreled
signalling signaling
signalled signaled
signaller signaler
totalling totaling
totalled totaled
tunnelling tunneling
tunnelled tunneled
tunneller tunneler
tranquillize or tranquillise tranquilize or tranquillize
tranquillizer or tranquilliser tranquilizer or tranquillizer
tranquillity tranquillity or tranquility
travelling traveling
travelled traveled
traveller traveler
woollen woolen
woolly woolly or wooly

-l- and -ll-

In contrast to the examples above, in the words below it is British English with -l- and US English with -ll-. Furthermore, it is the to form and present tense -s verb form that differ as well as a number of other forms.

British English US English
distil distill
enrol enroll or enrol
enrolment enrollment
enthral enthrall or enthral
extol extol or extoll
fulfil fulfill or fulfil
fulfilment fulfillment or fulfilment
instalment installment or instalment
instil instill or instil
skilful skillful
skilfulness skillfulness
skilfully skillfully
wilful willful or wilful

-c and -k

British English US English
leucoblast or leukoblast leukoblast
leucocyte or leukocyte leukocyte
sceptic skeptic
sceptical skeptical
scepticism skepticism

-qu and -ck

British English US English
cheque money check
chequer pattern checker

-xion and -ction

British English US English
inflection or inflexion inflection

-ce and -se

British English US English
defence defense
a licence a license
to license to license
offence offense or offence
a practice a practice
to practise to practice
pretence pretense
vice tool for gripping vise or vice

-re and -er

British English US English
calibre caliber
centre center
fibre fiber
goitre goiter
litre, millilitre etc. liter, milliliter etc.
lustre luster
manoeuvre maneuver
meagre meager
metre some meanings meter
meter measuring device meter (see note)
mitre miter
ochre ocher or ochre
sabre saber
sceptre scepter
sepulchre sepulcher
theatre theater or theatre
titre titer

Note: in both British and US English, meter is written with -er when it means a measuring device or to measure, for example:


The following words are also always written with -er in both British and US English:


Long and short endings

Some words in British English have a long ending, where the US spelling has a short ending. Compare the following examples. Note, however, that not all such words differ; for instance, both British and US English write diagram, histogram and synagogue.

British English US English
analogue analogue and analog
analog computing analog
axe ax or axe
catalogue catalog or catalogue
dialogue dialogue or dialog
gram or gramme etc. gram etc.
programme program
program computing program

In British English, the short forms analog and program are used in computing.

Other spelling differences

The following words are written differently in British and US English. On British and US vocabulary differences, see further below.

British English US English
draught some meanings draft
grey gray
plough plow
storey floor of building story
tyre vehicle tire