How to Spot the Difference: Key Points for Telling Genuine Luxury Watches from Evolving Counterfeits

It’s impossible to tell them apart by appearance alone

“The fakes are becoming increasingly sophisticated. In the past, you could sometimes identify them just by weight, but nowadays it’s standard for counterfeiters to match the weight to the genuine article down to the gram, making it difficult to judge authenticity based on a single point.

It’s also becoming more common that you can’t determine authenticity just by appearance. For example, with watches, you may need to disassemble them and inspect the inside. I’ve heard that some major buyback shops have strengthened their operations so that appraisers always check the internal mechanisms during assessments.”

So says Yoshio Aihara, CEO of IVA Inc., which operates Fake Busters, Japan’s leading AI authentication service. Fake Busters has so far handled authentication for sneakers, luxury bags, and apparel—including Mercari’s “Safe Authentication.” This year, they’ve continued expanding their categories, and in July, finally launched a watch authentication service.

While the luxury watch market has slowed due to China’s economic downturn, the secondhand watch market is thriving. According to major research firm Grand View Research, the market—worth $24.38 billion (about ¥3.7 trillion) in 2023—is expected to grow to $45.01 billion (about ¥6.8 trillion) by 2030. Prices for certain models have doubled or tripled over the past decade. Recently, the weak yen has attracted foreign buyers, while others purchase watches as investment assets. On top of dealers, players from other industries are entering the resale space, further fueling the boom.

Luxury watches have long been notorious targets for counterfeiting. They range from cheap knock-offs sold at overseas street stalls to near-perfect imitations that are difficult to distinguish from genuine ones. As Aihara notes, the quality of fakes has risen, and many can no longer be identified by outward appearance alone.

Fake Busters sets itself apart by combining AI with human appraisers. For watches, if authenticity can’t be confirmed from the exterior, they’ll go as far as examining the movement—the mechanism made up of hundreds of precision parts. Traditionally, appraisals relied only on external checks, so bringing AI into internal authentication is said to be an industry first.

“We’ve steadily expanded the product categories we handle, both to build the foundation of our company and because watches are an unavoidable category for authentication. They’ve always been counterfeited, and the market is enormous. But it’s also a very challenging field. For a buyback company, if they’re not sure, they can simply refuse to purchase. But as an authentication service, we need to deliver clear black-and-white results. That’s why we prepared carefully before launching this service.”

High-quality counterfeits are especially common with watches

What makes watch authentication so difficult?

“When authenticating, sometimes you can judge from the exterior, but in other cases, you don’t know until you actually open it up. When opening, you remove the case back, but depending on the material, some are hard to open or easily scratched, so you have to handle them very carefully.

For example, with Rolex, stainless steel models are made from a very hard material, so they don’t get scratched easily. But gold models are softer and more prone to scratches. We handle models worth millions, even tens of millions of yen, and we still need to give a precise judgment. I think that’s one of the real difficulties of watch authentication.”

Watches are also prone to high-quality counterfeits. New products are released at long intervals and variations are limited. Because of that, counterfeiters study a single product in depth to create extremely refined fakes that they can profit from over the long term. So, what details do experts focus on to spot such sophisticated copies?

“For the exterior, we look at the dial, crown, case back, and the logo on the clasp. By magnifying the font and the way it’s engraved, you can see differences. We also check the part that connects the dial to the bracelet—the bridge, called the lugs—and examine their length. If these dimensions are off, it’s usually a low-quality fake.

These days, however, there are many counterfeits with flawless exteriors. There are even some rare cases where only the exterior is genuine. Many high-end brands manufacture their movements entirely in-house, requiring proprietary techniques that counterfeit factories cannot easily replicate. So in practice, they often buy generic movements from specialized makers and fit them inside.”

By opening the case and closely inspecting the engraved logos and the condition of the screws inside, even counterfeits with perfect exteriors can be identified. Currently, Fake Busters authenticates watches from 50 brands, including Rolex and Patek Philippe, and they plan to expand the range of brands in the future.

The battle between ever-evolving counterfeits and the authentication technologies developed to detect them continues every day.