A technician replaces a compressor under warranty on a Tuesday. He is paid for that Tuesday. The part is covered, so the customer is not charged for it. Everyone involved considers the job finished.
It is not finished. The manufacturer owes labor reimbursement on that job, and that obligation has a clock on it. The clock started Tuesday.
Where the time actually goes
Most manufacturers set a filing window measured in days from the service date rather than from the date anyone got around to the paperwork. The exact number varies by manufacturer, by program, and sometimes by dealer tier, which is the first reason this is hard to keep in anyone's head.
The second reason is that the window is rarely the only requirement. A claim usually needs the equipment registered, the serial number matched, the failure coded correctly, and the part either returned or documented. Miss any one of those and the claim is rejected, and the rejection does not reset the clock.
So the real deadline is not the filing deadline. It is the filing deadline minus however long it takes to gather four things from three systems.
Why it slips
It slips because nothing in the shop is designed to notice. The work order closes. The technician moves to the next call. The office manager is reconciling yesterday. There is no screen anywhere that turns red.
And it slips quietly. An unfiled claim does not generate a complaint, a phone call, or a line on a report. It generates nothing at all. That is precisely what makes it expensive.
What to do about it today
Without changing anything, you can find out how big this is. Pull your closed work orders for the last ninety days. Filter to jobs where a part was replaced under warranty. Compare that list against the claims you actually filed.
The difference is your number. You do not need us to run that comparison, and we would rather you knew it either way.