The second pic is inside my 1946 red gold JLC. The serial number on the watch this thread is about dates the watch to 1942-ish.
Luxury watches come with a variety of numbers associated with them on the paperwork, case back, chronometer certificate etc., but which numbers are really significant? We are often afraid of giving the serial number away because of the growing replica market that has been taking these numbers and using them in a disingenuous way. However, without knowing it, many people mistake the watch serial number as the watch model number. For example, it is a common mistake on Cartier watches to blur out the case number instead of the watch serial number on online eBay listings. So… how do you find a watch model number? The answer? It depends on the brand. While some watches will not have a watch model number on the physical watch case, surprisingly, many of them do. The paperwork is always the first option for locating a watch model number, but unfortunately many times the papers are misplaced or lost. Here are some top luxury watch brands and some tips on how to find your watch model number.
But first, some common mistakes:
Jaeger Le-Coultre can be a little complicated, but we expect nothing less from such an intricate brand. There are sometimes three models that can identify one Jaeger LeCoultre watch. Some watches are more commonly identified by just one of these numbers, while others are referred to by all three. A Reverso, for example, is commonly known by the number on the back of the case. This model is usually in the form XXX.X.XX or a similar format. Jaeger Le-Coultre watches also have what is known as a “Q” model number. For instance, the Reverso Gran Sport has a “Q” model number Q2948102 and a case back number 295.8.51, both of which are searchable. The “Q” number will be on the paperwork and tag and the other on the case back. Occasionally, a longer watch model number will be listed on the paperwork as well as in a similar format to the case back number. This often does not search for the watch but is a genuine watch model number. Your best bet with JLC is the “Q” number or case back number.
Cartier watches, much like Jaeger LeCoultre watches, typically have a number on the case back and a unique identifier on the paperwork that will designate the model. The case back number (typically 4 digits) dictates what the case will look like. The materials can vary even with the same case back number, but the size and dimensions will be the same. Many people mistake the longer number on the case back, which is the watch serial number, for the watch model number. The 4 digit number is very important in identifying the watch. The other model number typically starts with a “W” and is found on the paperwork only. This number is the specific model number that will correspond to only exact matches of the watch. A Cartier Pasha will also have a case back number. With an exhibition case back it will still be on the outer edge of the case. If the watch case does not have a 4 digit model number, don’t worry, as some of the earlier models or quartz models do not have a case back number. In those instances, it might be necessary to find the size of the watch and compare the case to similar models. Seen below, 2730 is the case number.
Chopard is similar to Cartier. There will typically be a 4 digit case back number that is part of the model number. A Mille Miglia, for example, will have a 4 digit case back number and a model on the paperwork that is in the form of XX/XXXX, those last 4 digits being the same as the number on the case back. A specific example would be the Mille Miglia Gran Turismo XL which has a model number of 16/8457 and the case back will simply have 8457.
Breitling makes it easy to find the watch model number because the case back is marked with the model number. The paperwork will have the same model with the addition of a few numbers at the end designating the specific design of that watch. Sometimes, Breitling watches also have a chronometer certificate that is good to have with the watch, but that number will not identify anything having to do with the model. The good news is it typically searches by the letter and five digits seen on the case back. The trick is deciphering the watch model number, which usually begins with a letter, from the watch serial number.
Tag Heuer watches also have the watch model number on the case back. This should be the same model on the paperwork as well. Tag Heuer has a very clear cut modeling system that makes identifying the watch relatively easy. There is a serial number on the case back in addition to the watch model number so identifying which is significant is the only tricky part. Like Breitling, Tag Heuer watch models begin with letters, but the serial numbers can too, so it is typically the number “on top” or above the second listed number. An exhibition case back will be different since there is not as much space, the watch model number can sometimes stand alone. Model number is seen to the right above the displayed movement.
Bvlgari has a modeling system that appears on the case back. The model is essentially like a code that gives details about the watch. An example of a BVLGARI model number is BB 33 SGD. That model corresponds to a model in the BVLGARI BVLGARI line, 33mm with a steel and gold case, all logically designated by the letters. One model might have GMT at the end, signaling that it has a GMT function. The models typically make sense. A good indication that a BVLGARI is not authentic is if the letters do not make sense when looking at the watch, or there aren’t any numbers at all. Seen to the left on the case below are the letters DG 40 S GMT- this is a Diagono Model, 40mm, Steel with a GMT function.
For a Rolex watch, unfortunately if the paperwork is gone, finding the model number can be very difficult because it requires the removal of the bracelet or band. The model number is located between the watch lugs under the bracelet. One set of lugs displays the watch serial number and the other will show the watch model number. We recommend having the bracelet removed professionally if needed since removing the bracelet can easily result in a scratched case. The watch model number is usually referred to as the “style number” on Rolex paperwork, if there is paperwork on the watch. Luckily, there are some dial markers and case features that can usually give away a Rolex model number, but some models, such as the 18k Ladies Date-just line, can be difficult to discern.
Patek Philippe is another tough brand because many people assume the number on the case back is the watch model number, but that is actually the watch serial number. A Patek Philippe watch model number or reference number is located on the inside of the case back. We recommend having the case taken off professionally so as to not scratch the case in the process. We expect a bit of a hunt for the model number on such an exquisite brand.
Image from Master Horologer.
Omega is another example of a watch that puts the watch model number inside of the case. Omega watches do have a serial on the outside of the case however, that will search in Omega’s database and correspond with a model number. This database only dates back to certain period so anything vintage or retro might not search. Omega also uses the terminology “reference number” on their paperwork which is actually a pictogram card. Seen below “Ref.” is where the model number should be written.
Vintage wrist watches can be tricky because many times these models break the rules. You might find a model number on the case, for instance some Piaget models will search that way, but it is also very common to have the model number marked on the inside of the case back as well. Since most of the men’s vintage models do not have paperwork anymore, these are usually the hardest models to identify. Sometimes the caliber is used instead.