The short answer
Tortious interference allows a claim against someone who intentionally and unjustifiably causes another party to breach a contract with you, or who purposefully disrupts a reasonable expectation of business.
Where it fits in your case
When a competitor, former employee, or outsider disrupts your contracts or customer relationships.
What to expect
Contract interference requires a valid contract, the defendant’s knowledge, intentional and unjustified inducement of a breach, and damages.
Expectancy interference requires a reasonable expectation of a business relationship and purposeful interference.
Competition is generally privileged when pursued by fair means.
What we need from you
Contracts or relationship evidence, communications showing the interference, and lost business records.
Common misconceptions
“Taking our customer is interference.” Fair competition usually is not.
“We can sue the customer too.” Claims against the customer are usually for breach.