What the claim is aimed at
Tortious interference with a contract points at someone who was not a party to the agreement. Whatever your counterparty did is a separate question handled under the contract itself; this claim is about the outsider who reached in. What usually draws attention is what that third party knew and what they actually did about it. Ordinary competition is treated very differently from conduct that goes beyond persuasion, and where courts draw that line varies by state, which is why these matters are assessed on their particular facts rather than on a general rule. The loss also has to be traceable to the interference rather than to a deal that was already failing.
What to preserve early
Start with the contract itself and anything showing the third party knew it existed, which is often the piece that disappears first. Save the message or the meeting where your counterparty changed course, along with whatever explanation they gave you at the time, in writing if you can get it. Collect communications involving the third party, including anything forwarded to you by someone at the other company. Then document what the contract was worth to you and what you did to replace it. Text messages and messaging app threads are the most perishable items on this list, so copy them before phones are wiped or accounts are closed.
How these matters usually proceed
They are often brought alongside a claim against the contracting party, and sometimes alongside a defamation claim where false statements were part of what happened. Where the interference is ongoing rather than finished, whether some form of early relief is available becomes an immediate question, and that depends on the facts and the court. The window for bringing this kind of claim varies by state, and it is measured differently depending on how the interference is characterized. In the first conversation we look at two things: whether what the third party did is something more than competition, and whether the loss can be shown from records rather than inference.