Breach is the dividing line
In New York, a claim for interference with an existing contract generally requires that the third party actually broke the contract, not merely that the relationship ended or became less profitable. A customer who lawfully ends an agreement under its own terms, or simply declines to renew, usually does not support this claim. Where the contract could be ended at will, courts often treat the situation as interference with a prospective relationship instead, which requires more culpable conduct, such as wrongful means or acting solely to cause harm. Knowledge matters too: a defendant who did not know the agreement existed stands in a different position from one who read it. These distinctions decide many cases at the pleading stage.
When you are the one accused
Companies are often accused after hiring someone bound by a restrictive covenant or after taking a customer from a competitor. Ordinary competition is not wrongful by itself, and acting to protect an existing economic stake can be a defense in some situations. What tends to matter is what you knew, what you said, and whether anything confidential came along with the new hire or customer. Preserve emails, offer letters, and onboarding records, and do not delete messages after a demand letter arrives. Ask new hires in writing not to bring files from prior employers, and keep a copy showing that you asked.
Sizing up the claim from either side
For a party considering a claim, we look at the contract, how it ended, and what evidence shows the defendant's role rather than just its benefit. Damages need proof, often through lost profits, which can be hard to establish for a new relationship. Interference claims are frequently paired with a breach of contract claim against the party that left, and sometimes the contract claim alone is the cleaner path. For a party accused, we review the demand, assess exposure, and consider whether a response, a standstill, or a negotiated resolution fits. Either way, we discuss the business relationships involved, because litigation can affect them as much as any judgment.
