Where these disputes come from
Commissions and bonuses that go unpaid after someone leaves, and severance promised and then restructured or withheld. Equity described as vesting that turns out to carry conditions, and a fixed term agreement ended early. Duties, territory, or compensation changed without agreement, sign on or relocation money clawed back after a departure, and disagreements over what for cause meant in a particular document. A breach of contract employment agreement dispute usually involves two records that do not match: what a recruiter or a manager said, and what the signed document provides.
The documents that decide it
Gather the offer letter, the agreement and every amendment, and the commission or bonus plan as it existed during the relevant period rather than the current version. Add equity grant documents and the underlying plan, the handbook, and all separation paperwork including anything you were asked to sign on the way out. Three provisions decide most of these: language reserving discretion over incentive pay, a requirement that you still be employed on the payout date, and an integration clause excluding earlier promises. Contemporaneous emails confirming what was agreed matter most where the plan language is ambiguous, which it frequently is.
Which route fits
Many of these resolve through a demand and negotiation, particularly where the amount owed is already documented in the company's own records and the dispute is about willingness rather than arithmetic. Where the agreement contains an arbitration provision, the matter may never reach court at all. Unpaid compensation can sometimes also be pursued as wages through a state labor agency, which can be faster and less costly depending on the state and on what type of pay is involved. Deadlines apply and they differ by state and by the type of claim. The first conversation is usually about choosing among those routes rather than about the merits.