Online classifieds and marketplace apps make it easy to buy and sell almost anything, but that openness also attracts scammers who prey on trust and urgency. Most scams on these platforms follow familiar patterns once you know what to look for. Here's how the most common ones work and what you can do to protect yourself, whether you're selling a couch or buying concert tickets from a stranger.

The Overpayment Scam

A buyer offers to pay more than your asking price, often with a story: they have a shipping company handling pickup, a business account that can't send exact amounts, or they simply "trust you" and want to make it easy. They send a check, money order, or payment confirmation for more than the agreed amount, then ask you to refund the difference or forward it to a third party like a mover.

The payment is fake or will eventually bounce, but by the time your bank discovers this, you've already sent real money from your own account. You are left owing the bank the full amount.

  • Red flag: Any buyer who overpays and asks for a refund of the difference.
  • Red flag: Payment instructions involving a third party "agent," mover, or shipping company you didn't arrange.
  • Safe rule: Never refund money from a payment that hasn't fully cleared in your account, and be wary of any deal that requires you to send money back at all.

Off-Platform Payment Pressure

Many marketplaces offer built-in messaging, payment, and buyer protection. Scammers often try to move the conversation off the platform quickly, suggesting a payment app, bank transfer, gift cards, or a cryptocurrency payment instead of the marketplace's own checkout.

Once you're outside the platform, you lose any protection or dispute process it offers. If the item never arrives, or turns out to be fake or damaged, there's no record the platform can use to help you, and the scammer disappears with no way to trace them.

  • Red flag: A seller or buyer who insists on switching to text, email, or a personal payment app "to make things easier."
  • Red flag: Any request to pay by gift card, wire transfer, or cryptocurrency — legitimate private sellers rarely ask for these.
  • Safe rule: Keep the entire transaction, including payment, inside the marketplace's own system whenever one is offered. If a deal only works by going off-platform, that's a reason to walk away.

Fake Escrow Services

For higher-value items like vehicles, electronics, or collectibles, scammers sometimes suggest using an "escrow" service to reassure a nervous buyer or seller: your money is held by a neutral third party until the item is confirmed received in good condition. It sounds sensible, and real escrow services do exist.

The scam version is a fake website built to look professional, sometimes copying the name and logo of a real escrow company. You send payment to this site believing it's held safely, but it goes straight to the scammer, and the site vanishes or stops responding once the money clears.

  • Red flag: An escrow service suggested by the other party, especially one you've never heard of.
  • Red flag: A site that only accepts wire transfer or crypto, has poor contact information, or was created very recently.
  • Safe rule: If you want to use escrow, choose the service yourself, independently verify it, and never use a link sent to you by the other party.

Other Warning Signs Worth Knowing

  • Listings with unusually low prices for in-demand items, meant to create urgency and stop you thinking clearly.
  • Sellers who refuse a video call or in-person meeting and always have an excuse why they can't show the item live.
  • Buyers or sellers who pressure you to act "right now" before someone else takes the deal.
  • Requests for personal information — ID numbers, banking logins, or extra photos of payment cards — that go beyond what a normal sale requires.
  • Profiles that are brand new, have no reviews or history, or have reviews that look copy-pasted and generic.

How to Trade Safely

  • Meet in person in a public, well-lit place for local sales, and bring a friend if possible.
  • Use the marketplace's built-in payment and messaging tools rather than moving off-platform.
  • Inspect items in person before paying, or ask for a live video walkthrough if buying remotely.
  • Never send money to "unlock" a payment, cover extra fees, or refund an overpayment.
  • Independently look up any escrow, shipping, or payment service before trusting it — search the name plus words like "reviews" or "scam" and check how long the site has existed.
  • If something feels rushed or too convenient, slow down. Genuine buyers and sellers are rarely in a hurry to skip normal safety steps.

Most classifieds and marketplace transactions go smoothly, and a little caution goes a long way. If you do spot a suspicious listing or receive a strange payment, report it to the platform, contact your bank or card issuer if money has moved, and trust your instincts. A good deal doesn't require you to bypass the very protections designed to keep you safe.