Leading zeroes in phone numbers

Question

For a phone number like this:

05 40 33 25 98

If you were to say it to someone, would you start:

zéro-cinq quarante ...

Or because phone numbers in France usually start with zero, just:

cinq quarante ...

For other cases:

01 42 05 50 50

... quarante-deux zéro-cinq cinquante ... ?

01 40 13 00 28

... treize zéro-zéro vingt-huit ?

Answer 1

You should always pronounce leading zeros, and indeed say “zéro zéro” whenever a “block” of two digits is made of 0s.

01 47 20 00 01

is pronounced

zéro un, quarante-sept, vingt, zéro zéro, zéro un.