I own a supply store in Ontario Canada. I am a supplier of landscaping materilas. One of our contractors has an overdue debt of $20,000, agrees it is his debt but has no funds to pay it back. This debt is now in arreas of 120 day. I need to know what my rights are and the best way to collect this. Can I put a lien on his house or assets?

You could put a lien on anything the company owns to my understanding but not his personal home, as he and the business are 2 separate entities. Have you spoken to a lawyer or collection agency that could help collect on your behalf?

You cannot really do anything effective until you win a court judgment. I suppose you could ask a collection agency to report it with Dunn and Bradstreet, that's not going to help you much. Get a lawyer and have them served.