Is There a Single National FnF Law?
No — and this is the first thing to get right, because it explains why every FnF question seems to have a "it depends" answer. There is no single "Full and Final Settlement Act." Instead, five separate statutes each govern one slice of the settlement, and the law that applies depends entirely on which component is in dispute.
A salary delay is a Code on Wages issue. A gratuity delay is a Payment of Gratuity Act issue. A leave encashment cap is a state Shops & Establishments Act issue. A retrenchment compensation dispute, for workmen specifically, falls under the Industrial Disputes Act. Treating FnF as governed by "one labour law" is the single most common factual error in online guidance on this topic — and it leads employees to cite the wrong section when they escalate a complaint.