If a third party unfairly interferes with a business contract or relationship and causes damage, a tortious interference claim may be a viable option. Our tortious interference attorneys in Florida can help whether you believe your rights were violated in a contractual or non-contractual business relationship.Wrongful interference with a contractual relationship requires that there is a valid contract between two parties, a third party who knows the contract exists. Tortious interference is a commonly misunderstood and applied claim. It requires 1) a valid business expectancy, 2) defendant's knowledge of the expectancy. The tort of intentional interference with contractual relations is still an emerging economic tort in Canada. 4. The term Day as used in the Contract Documents will mean calendar day, unless otherwise indicated. 1.1.5.