At Helm Tickets we were a UK-first company with a UK audience, so we spelled "organiser" with an S. When we expanded to serve the US market, several people from the States got in touch through support to tell us we had typos across the website. "Organiser" was spelled wrong, they said, because they expected a Z.
They didn't read it as British English. They read it as typos.
The complaints came from event organisers, not ticket buyers. Ticket buyers weren't seeing the word "organiser" everywhere.
We hadn't planned for any of this. We assumed that moving into another English-speaking market meant the site would stay exactly the same, with nothing to translate. That assumption is what this chapter is about.