What does “NOS” mean?

NOS stands for new old stock. It describes a watch that is older or discontinued but was never sold to an end customer or worn. It may have sat in a retailer's inventory, a distributor's warehouse or a private collection for years, and it reaches the market in new condition despite its age.

NOS watches can be attractive to collectors because they offer an older reference in unused condition, sometimes with all the original packaging and paperwork. There are important checks, though. Mechanical watches that have sat for years may need a service, because lubricants age even when the watch has not been worn. The warranty card may be blank, dated recently or dated from the original sale, and each of those affects how the watch is presented and priced. Claims of NOS should come with evidence, such as original stickers, tags and untouched packaging.

A typical listing: “NOS Omega Speedmaster from 2015 retailer stock, never sold, stickers on, blank warranty card, recommend a service before daily wear.” Being open about servicing builds trust.