Telephone outside line access number

At hotels or offices, for example, you need to dial a "0" or "9" to access an external telephone line. Is there a specific term in English for that number.

The closest that I can think of right now is "outer line access number", but in the back of my head I hear a voice telling me that there is a simpler word/phrase for that.

Thanks!

Dial 9 for an "outside line".

external line or external access

Nor can I think of anything better than "outside line access number"

"Drucken Sie die Taste <___> um die Freizeichen zu bekommen."

You could use "Amtsvorwahl" but a lot of Germans don't know that word, though they'd figure it out in context.

woof.

FYI: http://dict.leo.org

defines "outside line" as "der Amtsanschluss" and vice versa. So I would agree with "outside line" as the correct term.

@BD
He said English, not German...

Actually, I was looking for a better English word/phrase than "outside line access number" (@Jeeves: thanks for the correction) and not a translation into German.

I guess that "outside line access number" isn't such a bad phrase.

Thanks for all of the responses.