As far as I'm aware, it's 10,000 miles/15,000 km, 20,000 miles/30,000km and then the next is 40,000 miles/60,000km isn't it?
My car hit 45,000km yesterday (yes it reads out in KM, no idea why!) and the 'Oil' and spanner symbols appeared on the dash. Read the service book, but it left me a bit...