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How to authenticate an IWC Portugieser

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    IWC Authenticity Check

    Recently here at the Relleb authentication center, we had the opportunity to perform our watch authentication service for one of my personal favorites – an IWC Portugieser.

    It is undisputedly one of the most successful and iconic watches of IWC. The first IWC Portugieser (or: “Portuguese”) dates back to the 1930s. The first Portugieser was built with a Calibre-74 movement of an IWC hunter pocket watch as a starting point. With a diameter of 43mm it was (especially at that time) one of the largest wristwatches of their time.

    Nowadays the IWC Portugieser has been refined by IWC to a beautiful looking wristwatch. The specific model we recently authenticated for one of our customers was the WC371604 model, with self-winding in-house movement of IWC. This is the IWC calibre 69355 movement, and a nice addition to the previously outsourced movements for the Portugieser enthusiasts in my view.

    But luckily this customer engaged Relleb in his watch-purchasing journey, and we helped him to achieve peace of mind with his purchase through our independent IWC Authenticity Check. Read more in this blog on how this process was conducted.

    This blog will help you better understanding what to look out for when determining the authenticity of an IWC luxury watch. Please note that this article is not exhaustive, as there are a lot of nuances and specific aspects that we check in addition to the checks which we have included below. Now let’s get to some details and checks we have performed on this particular IWC Portugieser WC371604.


    The IWC Portugieser

    This watch carries the following specifics:

    • Reference number WC371604
    • In-house IWC 69355 movement
    • Case size 41mm
    • Leather bracelet
    • Full set (box and papers included)
    • Issued in 2021
    • Automatic

    In this blog we will explain in 5 steps how we authenticated this IWC Portugieser, and will show you based on detailed pictures the level of scrutiny you can expect when engaging Relleb to perform an Authentication and Quality assessment for a watch you might be keen on buying. 

    How do I know if my IWC Portugieser is real?

    The IWC Portugieser is a popular model among watch enthusiasts and therefore unfortunately also amongst scammers. Fake IWC watches, both new and vintage, are put on the market as well.

    Just give it a go yourself when doing a quick online search for replica Portugieser watches. For prices ranging from €100 towards €1,000 there are fakes for sale. In general you could say the more expensive the more convincing, but in the end it is all the same: rubbish.

    At Relleb we like say that spotting a fake can be easy, but knowing if one is authentic is not. Only seasoned and experienced watchmakers can with absolute certainty distinguish a real one from a fakeAnd if you don't have the experience or knowledge, it might be quite hard to determine yourself. We truly believe you should engage an experienced watchmaker that you know and trust to ensure that you are getting the real deal. We hope this blog will give you some insights in how to perform an IWC fake vs real check.


    Step 1: check the box and papers

    The first step in the authentication process of this IWC Portugieser is to check if the box and papers that are included and correct. For this particular model the reference number is engraved in the case-back, which should also match with the papers.

    Documentationreferencesserial numbers should be in accordance with the watch at hand. The box and papers should also be original and time-correct. Which requires experience about boxes and papers that come with a specific model. Please note that not all pre-owned watches sold online contain original box and papers. Especially with vintage watches. This of course does not necessarily have to mean that the watch itself is fake or incorrect, but it does definitely help to look at the total-package if available.

    For this IWC Portugieser, all original papers and boxes were included. Meaning we have a full set at hand. We first scrutinized these to see if all was correct and in accordance with our expectations for this particular model. 

    The box and cards

    This watch is issued in 2021 and comes with the white outer-box in which the watch is included. In this box the leather pouch housing the watch is included. We always start our authentication service checking if we have a full-set such as this one:

    • Check for the correct outer box, which is the box that carries the watch (in this example for a 2021 IWC Portugieser the white box that carries the IWC logo on top
    • Validate if the authentic IWC Portugieser operating instructions are present
    • Validate if the authentic IWC Portugieser warranty booklet and card are present
    • How to authenticate the full set: Our watchmakers have more than 15 years of experience in working with IWC, and know what materials and documentation should be included in the full set. Including of what materials the set should be made of. A good watchmaker can derive a lot from the full set apart from the watch itself - and might already be able to raise some flags in some cases. Especially for vintage watches.


    Step 2: IWC case number check

    Serial numbers are used for IWC watches and are unique numbers used to identify all individual watches. For this particular IWC Portugieser model, the serial number was 626****.

    In case of a full set we perform the following checks:

    • Observe the serial number on the case (in this case on the back of the watch, on the case)
    • Check if the serial number on the Warranty card matches the serial number on the case. 
    • Check if the serial number on the movement 474**** is correct for this specific brand and model
    • Check if the caliber number matches with this specific brand and model, in this case the IWC calibre 69355 movement
    • During our inspection of the movement, we also verify and assess if the parts in the movement are of a level of quality that we would expect from IWC watches. For example, the level of finishing, details of the engraving, smoothness and crispness of the movement (depending on age, one might anticipate some requirements for servicing), and other details that confirm this watch only consists of original IWC parts. This is basically shown by the quality of the engraving that can only be concluded by an experienced watchmaker with years of experience with IWC watches.

    Serial number on the case back should match with the number on the papers and the warranty card.

    Step 3: How to authenticate an IWC movement

    Our experienced watchmakers observe the following during step 3 of our authentication service:

    • Verify if all components are IWC parts (by observing quality of finishing, IWC branding, use of IWC fonts, use of correct materials)
    • Make sure the complications and buildup of the movement are correct
    • We also authenticate if the watch carries the correct movement for the respective model, in this case the IWC calibre 69355 movement. Which is an in-house movement produced by IWC
    • Observe if the lubrication of parts is up to standards (and lubricate if needed)
    • No dirt or damage to movement parts
    • We also verify if the watch is serviced or if it needs service. We advise our clients if and when a watch should be serviced again. In this case we are talking about a 2021 watch, for which you would under normal circumstances not expect a service to be needed already (which was indeed not the case).

     Scrutinizing the finishing and quality of the movement and if the movement includes only authentic parts.


    Step 4: Making sure the case and bracelet are correct and in good quality

    In addition to checking if the watch is 100% authentic, we assess the quality of the watch. For example, we closely observe the case, glass, functioning of the complications, bracelet, clasp and other aspects of the watch. 

    During step 4 of the IWC authentication service, our watchmakers observe the following:

    • Observing quality of case finishing including brushing, materials used, the sharpness of the edges, crown, pushers, and overall condition (wear)
    • Observing the quality and finishing through a loupe including marks and text on the dial, material on the hands and plots and the depth of the text applied on the dial
    • Observing the quality and finishing of the bracelet including quality of the strap, the pins and material used.
    • Our watchmakers check if the bezel and finishing of the dial is correct and in accordance with IWC standards, and if the materials have been applied conform IWC standards. 
    • Verify is all complications are working properly
    • Observe the engravings in and details on the case (reference number and letters on the watch). These carry a specific finish that has to be observed with the eye up close.


    Step 5: Verifying waterproofness and timekeeping

    This last part on how to authenticate an IWC is focused on assuring quality. During step 5 of this authentication service, our watchmakers execute the following procedures.

    • Verifying timekeeping with a Timegrapher machine, this machine detects the beats per second and daily deviation in 1/10 of a second.
    • In addition there are multiple tools that can help with waterproofness testing (making sure a watch is waterproof) in case of watches sold as waterproof.


    Step 6: Fraud and theft check

    To ensure watches are not stolen, or any fraud or scams have been conducted with it. We perform a fraud and theft check with a database that has more than 70.000 watches registered. This applies for watches bought with Relleb protection on Chrono24 or on our Relleb marketplace. We noted for this example it did not match with a registration in the database. Thus this watch is concluded "clean".


    The conclusion on the IWC Authenticity Check

    We have briefly explained what we do in this blog about the authentication of a IWC Portugieser. This watch was sold as in "new condition" and passed our strict assessment for authenticity and quality. With our Authentication and Quality assessment the client (from The Netherlands) could enjoy peace of mind about the authenticity and quality of this watch.

    After the authentication and quality report was issued to the buyer, the watch was sent fully insured and with signature delivery to our customer. 

    How do I authenticate my IWC watch?

    That depends really, if you are a seasoned expert and/or IWC watchmaker you could possibly authenticate a IWC on your own. If you are not, you will not be able to perform certain authentication stepsOur advise would always be to have it authenticated by an experienced watchmaker.

    At first you need to be able to open the case back and dismantle the bracelet. In addition you need the experience to conclude if the materials used are correct, if IWC finishing is applied correctly, if the cards gloss and stickers are correct, verify the correct finishing of the dial, check the lubrication quality, verify the correct complications and buildup of the movement, assess quality of the pins used etc.


    How do I find my IWC serial number?

    IWC serial numbers are normally located on the case-back, and serial numbers generally look like 626****. IWC model numbers are used by IWC for their watches are unique numbers to be able to identify individual watches.

    How do you buy an IWC watch?

    The best places to buy authentic pre-owned IWC watches is on marketplaces such as Relleb, Or on eBay or Chrono24 with our Relleb authentication & buying service as a relevant add-on.

    Many certified pre-owned sellers like Chronext or Watchfinder&Co are most of the times far more expensive. They have more overhead costs and service every watch (in our opinion sometimes over-service watches) which adds up to the cost price of IWC watches (or any watch - for that matter). But, buying from private sellers bears risks and therefore we always advise to have an expert or watchmaker help you authenticate a watch.

    How can you tell a fake IWC?

    The most obvious things to look for when performing an IWC fake vs real check is to look if the dial and crystals are clean. Check if there are misspellings on on the watch. Check for the logo. Movement should be smooth. The quality should be as you would expect from IWC. And most importantly, if a price is too good to be true it normally is.

    Are IWC watches good quality?

    The International Watch Company is a luxury watch brand from Swiss and produces high quality watches. It is renowned for their high-quality watches by some of the best luxury watchmakers in the world, including our own. 

    Written by

    Marcel, watch enthusiast, co-owner of Relleb

    Last updated April 2, 2023

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