Online marketplace scams: how to buy and sell safely

Why marketplaces attract scammers

Marketplace listings are ideal for criminals. You are dealing with a stranger, the platform rarely checks anyone’s identity, both sides are hoping for a good deal, and a lot of people are comfortable paying by bank transfer or payment app, where money moves fast and is hard to bring back.

The scams below are not exotic. They are the same four or five tricks, reused constantly. Once you can recognise them, most attempts become obvious within a message or two.

Scams aimed at sellers

The fake payment

A “buyer” says they have paid through Zelle, Venmo, PayPal or a bank transfer. They send a screenshot or an email that looks official. Sometimes they say you must “upgrade your account” or pay a fee before the money is released. No money has moved at all. The National Cybersecurity Alliance lists this as one of the most common marketplace scams.

The rule: only believe your own banking or payment app, opened by you. Never click a link in a message to “confirm” a payment, and never pay a fee to receive money.

The overpayment (or fake cheque)

The buyer sends more than your asking price, by cheque or by payment app, and then asks you to refund the difference, or to pass it on to a “shipping agent”. The FTC explains why this works: the cheque can look completely genuine, even to bank staff, and banks can take weeks to find out it is fake. By the time it bounces, you have already sent real money, and you are the one who owes the bank.

The FTC lists “someone sends a cheque for more than the selling price” as a warning sign in its own right. The rule: never refund an overpayment. Tell the buyer to sort it out with their own bank, and do not hand over the item until the exact amount has genuinely cleared.

The code-stealing “buyer”

A buyer says they want to “verify you are real” and asks you to read out a six-digit code they have sent to your phone. That code is a login or password-reset code for one of your accounts. Anyone who asks for it is trying to take the account. See our OTP interception checker for how this works.

Links that steal your details

Some buyers send a link to a “secure payment page” or a courier tracking form. These are phishing pages built to collect your password or card number. Paste any link into our link safety checker before you open it, or better, do not open links from strangers at all.

Scams aimed at buyers

• Too good to be true. A new phone at half price, a car far below market value. Scammers copy photos from real listings and rely on bargain hunger.
• Deposits for items you have not seen. “Send a deposit to hold it” is a classic. The item does not exist.
• Pressure to move off the platform. Once a conversation moves to email or messaging apps, the platform’s protections and records are gone, and so is any chance of help.
• Awkward payment methods. Gift cards, wire transfers, cryptocurrency, or “friends and family” transfers. The FTC says only scammers insist on these.
• A fake courier or escrow service. The seller says a third-party company will hold your money. The “company” is a website the scammer built.
• New or empty profiles. No history, no reviews, no mutual connections, often with a stolen profile photo.

Our guide to fake online stores covers the same patterns for shops that look professional but are not.

A safer way to do it: sellers

1. Keep all messages inside the marketplace app.
2. Expect to meet in person for cash for most items. If a buyer insists on paying remotely, treat it with suspicion.
3. Check your own bank or payment account directly before you hand over the item, and confirm that funds have cleared, not just “pending”.
4. Refuse overpayments. Never refund, forward or “pass on” money.
5. Never share a code that arrives on your phone, and never click a payment link sent to you.
6. Meet in a public place, ideally somewhere with cameras and other people, and bring someone if you can.

A safer way to do it: buyers

1. Compare the price with similar listings, and run a reverse image search on the photos. A photo that appears on other sites is a red flag.
2. Check the seller’s history, reviews and mutual connections.
3. Inspect the item in person before you pay, and test it. Bring a friend for expensive items.
4. Pay only after you have the item in your hands, or pay through a method with protection. On PayPal and Venmo, choose “goods and services” (“purchase”) and not “friends and family”, which removes protection. This may carry a fee, and it is worth it.
5. Do not carry large amounts of cash.
6. Walk away if the seller refuses to meet, pushes you to hurry, or asks for money first.

What a scam conversation looks like

Seeing the pattern once makes it easy to spot next time. These are typical, shortened examples (written by us to illustrate, not real messages).

The overpaying buyer. “Hi, is this still available? I will pay your asking price plus extra for my courier to collect it. I am sending a cheque now. Please send the difference to my courier once it arrives.” The warning signs are the extra money, the courier you have never heard of, and the instruction to send funds before the cheque has been checked by your bank.

The deposit seller. “Lovely bike, it is in another city so I cannot meet. Send a 20% deposit to hold it and I will post it on payment.” The warning signs are that you cannot see the item, they cannot meet, and the payment is upfront.

The helpful verifier. “Google is going to send you a code so I know the listing is real. Please read it to me.” The warning sign is the request for a code. That code is the key to one of your accounts.

In each case, a real buyer or seller would be happy to pay in person, wait for a bank transfer to clear, or let you inspect the item first. Anyone who resists those simple steps is telling you something.

Higher-risk categories: cars, rentals, tickets and pets

The bigger the sum, the more effort scammers put in. Take extra care with:

• Vehicles. Fake sellers use cheap prices and a story about being overseas or in the military. Never pay for a car you have not seen, tested and checked the paperwork for. Meet at a safe place and confirm the seller’s identity matches the registration.
• Rentals. A “landlord” who cannot show you the property, wants a holding deposit by transfer, and has copied the photos from another listing. Visit in person, and be wary of any rent that is well below similar properties.
• Tickets. Resale tickets can be fakes or already used. Use the venue’s official resale system where one exists.
• Pets. Fake breeders post cute photos and ask for deposits, then add “shipping fees” or “insurance”. Insist on a video call, a visit and paperwork before paying anything.
• Electronics and phones. Check serial numbers, test the item and be wary of “locked” or “blacklisted” devices. Take a friend who knows what to look for.

For all of these, a rule of thumb works: if you cannot see it, hold it and try it before you pay, do not pay.

If you have been scammed

1. Stop all contact and do not send any more money or details.
2. Contact your bank or payment provider straight away. Speed improves your chances.
3. Report the listing and the account to the platform.
4. Report it: in the US at ReportFraud.ftc.gov, or find your country’s agency on our Report a Scam page.
5. If you sent gift cards, crypto or a wire transfer, contact the card issuer or sending company immediately and ask whether a reversal is possible. Our first 24 hours checklist has the full list.

Sources

• FTC: Fake check scamsAccessed October 12, 2026
• National Cybersecurity Alliance: Stay safe on Facebook MarketplaceAccessed October 12, 2026
• FTC: How to avoid scams when shopping onlineAccessed October 12, 2026

Published October 12, 2026. We check every claim against the sources above and say clearly when something is advice rather than fact. This guide is general information, not legal or financial advice. Dollar amounts are in US dollars, as reported.