Serial Lookup

Longines original serial number series began in the late 1860s/early 1870s at or shortly after the factory in St Imier was constructed. By the end of the 1960s, this original unbroken series was nearing 15,000,000. However throughout the late 50s and into the early 70s electronic and quartz movements began entering the watch market and provided a considerable source of stress for traditional mechanical watch makers and in response a series of consolidations happened in the Swiss watch industry. Longines starting in 1970, began a merger into conglomerate ASUAG (a holding company set up by the Swiss government during the great depression) with the goal of consolidating and streamlining the production of watches so that the industry as a whole could utilize its economies of scale to decrease costs and better compete with the emerging quartz watches. The merger would not become fully complete until 1972. Starting around this time, a new movement serial number series began that started at 50,000,000. Interestingly, when getting an extract from the Longines archives for a watch with a movement serial that starts in the 50,000,000 and greater range, the extract will come back noting the case and not the movement serial number. These case serial numbers appear to follow the original series (though there are some inconsistencies especially in the years 1969-1971).

All serial number dates above are approximate and based on information originally published in The Complete Price Guide to Watches series of books by Cooksey Shugart and Richard Gilbert. All publicly available serial number datasets for Longines watches appear to be based on this same source. I hope one day to be able to release a more accurate dataset. For a truly accurate determination of the age of a watch, I strongly recommend you get an Extract from the Archives from the Longines Heritage Department.