As an author, you often have to write for a particular market, so today I will highlight three of the key spelling differences between the UK and the US:
OU vs. O
S vs. Z
RE vs. ER
If you are writing fictional works (or, indeed, non-fiction too) for a publisher outside your country, check their spelling requirements prior to submission to avoid either outright rejection of your work or, at best, a lot of fiddling come editing time. As an author, you want to give your story the best chance of success right from the outset.
Set your document to UK or US spelling (as appropriate) from the start as this will highlight most of the errors. However, watch out for RE vs. ER as Word’s spell check does not always pick up on that one!