421. The revocation of a registration certificate is effective from the date of service of the decision upon the holder.
Notwithstanding the first paragraph, in the cases described in subparagraphs 2 and 3 of section 419, revocation is effective only upon the expiry of 15 days from service upon the holder of the decision to suspend where the holder has not made representations within six days from receipt of the decision. Revocation is effected by operation of law.
In all cases, the decision to revoke shall be served by personal service or by registered or certified mail to the last known address of the holder.
A judge of the Court of Québec may authorize a mode of service different from those provided for in the third paragraph.
The holder shall return his certificate to the Minister immediately after being served.