Example scenario · illustrative, not a real seller
An example seller doubts a bag’s stitching before listing, and months later a buyer says some headphones are fake. Both cases turn on the evidence folder.
What you’ll get
- eBay's counterfeit policy in plain terms.
- Four steps when you doubt your own stock.
- Four steps when a buyer makes a claim.
- An evidence folder that settles questions.
- Sourcing habits that lower the risk.
Two ways a fake reaches your table
Counterfeits arrive in a reseller's life in two ways. Sometimes you start to doubt an item you bought: the stitching on a designer bag looks off, or a pair of headphones feels too light. Other times a buyer messages after delivery to say the item you sold them is fake. Both moments call for the same calm approach: stop, check, document and use the platform's process. Neither calls for guessing, arguing or quietly listing the item somewhere else.
This guide covers what to do with a suspected counterfeit item, using eBay's counterfeit policy and return request help, and Mercari's returns article, checked November 8, 2026. It doesn't authenticate anything, and it isn't legal advice.
What the platforms say
| Source | Rule |
|---|---|
| eBay counterfeit policy | Counterfeit or fake items aren't allowed; you may list an item only if you're certain it's genuine |
| eBay counterfeit policy | Using the term "dupe" with a brand name isn't allowed and can suggest a counterfeit |
| eBay counterfeit policy | Examples include electronics such as phones, headphones, chargers or cables sold under a trademark without authorization |
| eBay return request help | If an item doesn't match the listing description, you'll generally need to accept the return |
| Mercari returns | Buyers can request a return within 72 hours of delivery if an item is inauthentic or counterfeit |
eBay's policy also points rights owners to its Verified Rights Owner (VeRO) program and other members to its reporting process.
Step 1: Stop before listing stock you doubt
Steps 1 to 4 cover an item you bought and now doubt. If you have real doubts, don't list the item. "Certain it's genuine" is eBay's standard, and doubt isn't certainty. Moving it to a different platform doesn't solve the problem.
Step 2: Check with care
Compare the item against the brand's own product information, look for the details that matter in that category, such as labels, serial numbers, stitching, materials and weight, and use a reputable authentication service where one exists for that category. The authenticity before price manual covers checks by category.
Step 3: Record what you found
Photograph the details you checked and write a note with the date and result. Add it to the item's folder by SKU.
Step 4: Decide its fate
If you can't establish it's genuine, don't sell it as the brand. Many sellers simply write it off and dispose of it. Selling a known or likely fake as genuine misleads buyers and breaks platform rules; describing a fake as a "dupe" with the brand name is also against eBay's policy.
Step 5: Reply calmly when a buyer says it's fake
Steps 5 to 8 cover a buyer's claim after delivery. Thank the buyer, ask for photos showing what concerns them, and say you'll handle it through the platform's return process. Don't accuse the buyer of swapping the item in writing; that's a separate concern handled through the platform.
Step 6: Review your own evidence
Open the item's folder: your listing photos, authenticity notes, purchase receipt and packing photos. Compare the buyer's photos with yours, especially serial numbers, labels and distinctive marks.
Step 7: Use the platform's process
On eBay, an item that doesn't match the description generally needs to be accepted for return. On Mercari, inauthentic items are a return reason within 72 hours of delivery. Respond within the platform's deadlines and let its process decide. The return arrives manual covers documenting what comes back.
Step 8: Inspect the return
When the item comes back, photograph it on arrival and compare serial numbers and marks with your original photos. If it isn't the item you sent, report that through the platform with your evidence.
Worked example: an evidence folder that settles questions
In this chosen example, a seller keeps this folder for a used pair of branded headphones.
| File | Purpose |
|---|---|
| Serial number photo | Unique identifier matched on return |
| Box and label photos | Packaging details |
| Weight on scale | Physical comparison |
| Receipt from purchase | Where it came from |
| Authentication note | What was checked, when, and the result |
| Packing photo | What shipped |
When a buyer later questions authenticity, the seller can respond with facts, and if a return comes back with a different serial number, there's a photo to prove it.
Reduce the risk at sourcing
- Be cautious with categories that are heavily counterfeited, such as luxury bags, sneakers, perfume, electronics accessories and sports jerseys.
- Pay sourcing prices that leave room to walk away if authentication fails.
- Prefer sources where you can inspect before buying.
- Learn the details that matter in the categories you buy most.
Wording: Never use "inspired by", "dupe" or similar phrases with a brand name to sell an item you can't establish is genuine.
Common mistakes
- Listing an item you have doubts about and hoping.
- Moving a doubtful item to a different platform.
- Arguing with a buyer instead of using the return process.
- Not photographing serial numbers before shipping.
- Calling a fake a "dupe" with the brand name.
Certain, or not listed
If you can't establish an item is genuine, it doesn't get listed as the brand, on any platform. Check and document before listing, keep serial photos, and handle buyer claims through the platform's process.
Worked example · hypothetical, not a real seller
Keep the example in view
| Chosen file | Purpose |
|---|---|
| Serial number photo | Matched on return |
| Box and label photos | Packaging details |
| Authentication note | What was checked and when |
| Packing photo | What shipped |
Before the next transaction
With JavaScript and browser storage, only checked-step IDs can stay on this device. No buyer details or amounts are saved.
Practical questions
When can I list a branded item on eBay?
eBay's counterfeit policy says you may list an item only if you're certain it's genuine.
Can I call an item a "dupe" of a brand?
No. eBay’s policy says using "dupe" with a brand name isn’t allowed and can suggest the item is counterfeit.
Do I have to accept a return if a buyer says it’s fake?
On eBay, items that don’t match the description generally need to be accepted for return; Mercari lists inauthentic items as a return reason within 72 hours of delivery.
What if the returned item isn’t the one I sent?
Photograph it on arrival, compare serials and marks with your originals, and report it through the platform with that evidence.
Do this next · one concrete move