What is an in-service date and why does it matter?

The in-service date is the day a vehicle was first put into use, and it is when the factory warranty clock starts. It matters most with used cars, demos and loaners: a 2-year-old car may have an in-service date later or earlier than you expect, which changes how much warranty time remains. Ask the seller for the in-service date and confirm it with a franchised dealer for that brand using the VIN. OffLot's Open lot mode checklist includes asking about remaining warranty.