Omega serial numbers are typically found engraved on the movement itself on vintage models produced before the mid-2000s. To access the movement serial number, the case back generally needs to be opened, which is commonly recommended to be done by a qualified watchmaker. These movement serial numbers can often be cross-referenced with published Omega serial number tables to determine an approximate production year, though these tables typically indicate when the movement was manufactured rather than when the complete watch was assembled or sold.
On modern Omega watches produced from roughly the mid-1990s onward, an additional serial number is often found engraved on the case, typically on the lug area or between the lugs at the 6 o'clock position. This case serial number can sometimes be used by Omega boutiques and service centers to look up the watch's records. Beginning in the 2000s, Omega also introduced the PIC number (Product Information Code), a 14-digit reference number that encodes detailed information about the watch including the collection, material, bezel type, dial color, and movement type.
The PIC number system provides a structured way to identify modern Omega watches and is commonly found on the case back, warranty card, and accompanying documentation. Collectors often use the PIC number to verify that a watch matches its paperwork. However, vintage Omega watches predate this system, and their identification typically relies on the movement serial number, caliber number, and reference number stamped on the case back or inside the case back. Dedicated Omega databases and collector communities maintain extensive records to assist with decoding these older numbering systems.