It’s Second Hand September, and the resale economy is booming; one in four fashion buys we make will be pre-loved or vintage.

My enthusiasm for recirculating second-hand has been known to get out of hand. Mr Siegle has often been left searching for a cherished garment only to discover I’ve recirculated it. Recently I donated a pair of unworn, genuine Jimmy Choos, taking the charity’s ‘give us something you’d give to a friend’ very literally. Earlier this summer I wore a 100-year-old dress to a party even though the back disintegrated through the function.

I've been buoyed by the take-off of second-hand in this country, the death of the stigma and the possibilities of breathing life into apparel. I never want it to end.

But there’s a big threat. The success of resale has attracted fakers, with a quarter of pre-loved clothing buyers having unintentionally purchased counterfeits in the previous year.

This is no longer just about a fake Gucci T-shirt carrying a logo it has no right to. Fakery has followed us much deeper into the second-hand wardrobe. Is that dress genuinely vintage? Is that jacket really military deadstock? Is the ‘archive’ piece what the seller claims it is, or are they spinning a yarn? The fakers aren’t just exploiting brands; they’re exploiting the stories, scarcity and romance that make us want to hunt second-hand in the first place.

To fight back, I consulted four very different fashion insiders for a mini masterclass: Vinted, with a critical vantage point across 17.4 million UK customers; anti-counterfeiting expert Alastair Gray, who knows how the fakers operate; Vestiaire Collective authenticator Victoire Boyer-Chammard, with one of the most discerning eyes in the business; and Christopher Raeburn, pioneer of remaking military surplus and utility clothing, who has spent 20 years reading garments as you or I would read a book.

According to the in-house experts at secondhand resale platform Vinted, the five tips below are a great starting point.

Do your homework. Familiarise yourself with how the item looks new and what a realistic second-hand price would be.

Investigate the seller. Browse their profile and recent reviews for clues about trustworthiness.

Ask for evidence. Request additional photographs and proof of authenticity if it isn’t visible.

Beware the irresistible bargain. “If it seems too good to be true, it probably is… that sold-out item at half price? Be cautious.”

Know your protection. Vinted offers physical verification for adult fashion pieces over £85, covering more than 6,000 brands, for £10. Buyers also have two days to confirm receipt or raise a concern. I spotted that in a City of London Trading Standards factsheet (I read all the fun stuff!). So don’t leave that parcel in the hall.

Now you've got the basics under your belt; it's time to start reading up on how exactly to spot a counterfeit. Alastair Gray, Director of Anticounterfeiting at the International Trademark Association (INTA), shares the following.

Know that they’re watching the trends. Counterfeiters follow social-media trends and can even take requests from sellers about what to produce. If we’re suddenly desperate for it, chances are they’ve noticed too.

Look at the presentation. Are you seeing the actual item or photographs copied from a retailer? Look for close-ups of labels, stitching, serial numbers, packaging and swing tags.

Learn the language of fakery. “Factory overruns”, “seconds”, “mirror quality” and “1:1 quality” can be used to give non-genuine goods an air of legitimacy. “New without tags” can also warrant scrutiny.

Compare it with the real thing. Gray recommends reverse-image searches and reliable references. “Is the thread or ribbon on the swing tag navy or white on the genuine? Is the size label on the side instead of underneath the neck label?” Detail counts.

Investigate their wardrobe. Is everything “new with tags”, or are there multiples in different sizes and colours? Does this look like somebody clearing their wardrobe or somebody shifting stock?

Don’t let the price fool you. A suspiciously low price remains a warning sign. But counterfeiters can also price fakes closer to the genuine article because a realistic price makes them more convincing. Cheap can be a red flag; expensive isn’t proof.

Next step: understanding how an authenticator actually examines a piece, according to Victoire Boyer-Chammard, Senior Brand Manager & Authentication Specialist at Vestiaire Collective.

Did this piece ever exist? “I always start with the bigger picture before looking at the smallest details. The first question to ask is: did this model actually exist?” Recognise the house’s DNA: typography, signature prints, cut and even motifs on buttons.

Forget the ‘magic’ tell. “Rather than looking for one ‘magic’ sign of authenticity, look at the item as a whole and ask whether all its details make sense together.” Materials, construction, typography, hardware, finishes and branding all matter.

Use your hands, and your nose. “Authenticators develop a very trained eye, but also use touch and even smell.” With leather, the feel and smell can provide information about its material and tanning.

Don’t let a receipt settle the case. “Serial numbers, labels, packaging, receipts and even technological elements such as NFC chips can now be reproduced by counterfeiters.” No single element is proof.

Vintage plays by different rules. Typography, labels, zippers, hardware and construction change over time. Ask whether “the different elements of the piece tell the same historical story”.

Last but by no means least, some final tips from designer Christopher Raeburn. A pioneer of remade fashion, he has an illustrious history of turning authentic military and utility surplus into contemporary garments and a forensic eye for fabric, construction and hardware.

Start with the material. “Before looking at a label, I’d look at the fabric itself: its weight, handle, wear and ageing. Good vintage materials often tell you quite a lot before anything else does.”

Turn it inside out. “The exterior tells you what something looks like; the interior often tells you how it was made.” Seams, reinforcement, linings and finishing reveal quality and construction.

Interrogate the hardware. Zips, buttons, buckles, snaps and adjusters are clues. Look at whether they feel appropriate, how they have aged and “whether they were designed to perform rather than simply decorate”.

Ask for its backstory. “Provenance matters. Where did it come from? What was it originally made for? What can the seller genuinely tell you about it?” With good vintage, “the story should become more convincing as you examine the details, rather than less.”

Don’t be frightened of repairs. “Repairs aren’t necessarily a negative.” A thoughtful repair can be evidence that something was valued enough to keep in use, “provided you understand what is original and what has subsequently changed”.

This is the advice I’m taking to heart and adding to my skillset. Remember, the answer to increasingly sophisticated fakes is an increasingly sophisticated shopper. Have a great SHS!