Do I have to dial zero first to get an outside line?

How to say “Do I have to dial zero first to get an outside line?” in Japanese

In Japanese

外線(がいせん)にかけるときは、先(さき)にゼロをダイヤルするんですか。

Gaisen ni kakeru toki wa, saki ni zero o daiyaru suru n desu ka.

Do I have to dial zero first to get an outside line? in other languages