How to Verify an Online Seller or Buyer Before You Pay

Why a quick check pays off

Peer-to-peer marketplaces run on speed and scarcity, and scammers depend on both. The listing is priced to make you move before you think, the seller has 'three other people interested', and payment is requested somewhere the platform can't see. A short routine before you pay — or ship — filters out most of it.

Online shopping is consistently among the most-reported fraud categories to the US Federal Trade Commission, and fraud originating on social media produces higher losses than any other contact method the FTC tracks — precisely because those sales sit outside any marketplace's buyer protection.

Know the scripts before you meet one

Marketplace fraud is not improvised. There are half a dozen recurring scripts, and recognising the opening line of one is faster than any verification step.

• •The off-platform pull: continue on WhatsApp or Telegram 'to avoid fees'. The fee is buyer protection, and giving it up is the point of the request.
• •The overpayment refund: a buyer sends more than the price, often with a forged confirmation email, and asks you to refund the difference. The original payment is later reversed and you're out the refund plus the item.
• •The verification code scam: a 'buyer' asks you to read back a six-digit code they've just texted you, framed as proving you're not a bot. It's a Google Voice or account-recovery code, and handing it over registers a number or takes an account in your name.
• •The pickup ambush: a meeting at a residential address or quiet car park. Meet at a police station safe-exchange zone or inside a busy shop, in daylight.

Run the handle they gave you

Every marketplace identity comes with a handle: a shop name, a username, a Cash App $cashtag, a Venmo tag. That handle is your best verification tool, because legitimate sellers want it findable — they reuse it on Instagram, Etsy, Depop and Poshmark to build the reputation their business runs on. A throwaway identity has no such incentive and no such history.

AliaScan checks a username or $cashtag against 400+ platforms and links each public profile. A seller whose handle traces to a consistent presence spanning years is a very different proposition from one whose handle exists nowhere else. It reads public pages only — it can't tell you who owns a payment account.

• •Search the shop name and the personal handle separately; they're often different and both matter.
• •Check a $cashtag or Venmo tag before sending money. Payment handles are the ones most likely to be recycled between scam accounts.
• •Look for the handle on a platform with public reviews — an Etsy, Depop or Poshmark rating history is corroboration a social account can't give you.
• •A handle leading nowhere is a reason to slow down, not proof of fraud. One leading to accounts with an unrelated name and location is a much stronger signal.
• •Compare account age across platforms: present on four platforms since 2019 is credible; four accounts created last month is a set.

Check the listing and the account itself

The listing usually gives it away before the seller does, and the first two checks take about fifteen seconds each.

• •Reverse image search the item photos, not just the profile picture — stolen listing images are the single most common tell, and TinEye sorted oldest-first shows where the photo came from. Then ask for a fresh photo of the item with today's date written next to it.
• •Check creation date and review count together. Facebook Marketplace shows 'Joined Facebook' on the seller panel; Depop, Poshmark and eBay display a join date and feedback history.
• •Price sanity: an item at 40% below every other listing is not a bargain, it's the hook.

Pick the payment method by how recoverable it is

Verification tells you who you're probably dealing with. The payment method decides what happens when you're wrong, and it's the only part fully under your control.

• •Credit card, on-platform: the strongest position. The US Fair Credit Billing Act allows a dispute within 60 days of the statement, and network chargeback rights typically run to around 120 days. Marketplace buyer protection sits on top.
• •PayPal Goods and Services: Purchase Protection with a 180-day dispute window. Paying the fee rather than using Friends and Family is the cheapest insurance in the category.
• •PayPal Friends and Family: no purchase protection whatsoever. A seller who insists on it is asking you to waive your only recourse, and that request alone is reason to walk.
• •Zelle, Cash App, Venmo and other peer-to-peer transfers: designed for people you know and trust, with essentially no dispute process for a completed authorised payment. Bank transfers are recallable only within hours, if at all.
• •Gift cards and cryptocurrency: irreversible by design, untraceable in practice, and requested by no legitimate seller anywhere. This is a hard stop, not a caution.

If you're the seller

Sellers are targeted at least as often as buyers, and the scripts differ enough that buyer advice doesn't cover them. The core rule: a payment is not received until it has cleared in your own account, viewed in your own banking app — not in an email, an SMS, or a screenshot the buyer sends you.

Never read back a verification code; no legitimate buyer needs one. Ship only to the address on the order, never to a 'forwarding agent' the buyer nominates, and use tracked delivery with signature so a false non-delivery claim can be answered. Refunds go back through the original payment route only — never as a separate transfer, which is what the overpayment script is engineered to produce.

The golden rule, and what to do if it goes wrong

If someone pushes you to pay in a way you can't reverse, or off the platform that protects you, that is the entire signal and no subsequent reassurance changes it. Slowing down costs you a listing; not slowing down costs you the money.

If you've already paid, open a dispute with your card issuer the same day — the 60-day Fair Credit Billing Act window runs from the statement, not from when you noticed. Screenshot the listing, profile, conversation and payment record first, because scam accounts are removed quickly and the evidence goes with them. Report to the marketplace, and in the US to reportfraud.ftc.gov and ic3.gov; in the UK, Action Fraud.