The Ministry proposes that no collection agency or collector should exceed three unsolicited contacts to a debtor in any seven-day period.
The following types of contacts would be included within this restriction:
Contacts by telephone, facsimile, e-mail, text message and personal contact, or any other form of contact not specifically excluded;
A call by an automatic dialing device if that call connects to a live person or answering machine whether or not a collector comes on the line;
Messages left for the debtor or with a person referenced in Section 1 of the Harmonized Practices would be a contact for this purpose: member of debtor's family or household, any relative, neighbour, friend or acquaintance or the debtor's employer.
The following types of contacts would not be included within this restriction:
Contacts to third parties to locate a debtor;
Mistaken contact of a third party (e.g., through an accident, the collector could realize they had left the message with the wrong number and not have this contact count against allowed number);
Incomplete contacts (e.g., the phone rang and no one answered - note causing a phone to ring excessively is however itself potentially a form of harassment and not permitted);
Contact by conventional letter-post (on the basis that conventional post is not a disruptive form of contact and is also more self-limiting due to cost);
Contacts that the debtor consented to or solicited in advance (e.g., "I'm busy now, call back in half an hour." - the call in half an hour does not count).
This is from:
Adopting the Harmonized List of Prohibited Collection Practices - Government of Ontario (Canada)
The does and don'ts.