The shared architecture. Schemes that look nothing alike on the surface tend to be assembled from the same five parts.
First, contact is initiated by the other side, which reverses the normal direction of trust: you did not go looking for this investment, this refund, this warning or this relationship. Second, a story explains why the ordinary channel cannot be used — the account is frozen, the deal is off-market, the agency is calling instead of writing, the person cannot meet in person yet. Third, urgency is manufactured so the target does not have time to check, and the urgency is almost always attached to a consequence rather than an opportunity. Fourth, secrecy is requested, often framed as protecting the target from an investigation or from a family member who would not understand; this is the step that isolates them from the person who would otherwise ask an obvious question. Fifth, the payment is routed through something that cannot be pulled back: a wire transfer, a cryptocurrency transfer, a gift card code, a peer-to-peer payment app, cash, or a courier.
The payment method is the most reliable tell available, and it is a tell precisely because it is deliberate. No legitimate government agency, utility, bank fraud department, court or employer needs to be paid in gift card codes or cryptocurrency, and no legitimate counterparty needs the payment to be irreversible. When the requested method changes after the first attempt fails, that is the same signal repeated. The reason this works as a rule of thumb is that the choice of rail is one of the few parts of a scheme the operator cannot disguise.
Verification is a step, not an attitude. The useful version is independent: look up the institution's number yourself rather than using the one you were given, call back on it, and check registration where the pitch is an investment — an investment adviser's registration at adviserinfo.sec.gov, a broker's at FINRA's BrokerCheck, and a state-registered adviser through the state securities regulator. An entity that cannot be found in any of them is a useful finding on its own.
Where to report, and why it is worth doing even when nothing comes back. The Federal Trade Commission takes consumer fraud reports at ReportFraud.ftc.gov, and identity crime specifically at IdentityTheft.gov, which is the statutory hub and produces the report on which several federal remedies depend. The FBI's Internet Crime Complaint Center at ic3.gov takes reports of internet-enabled fraud, and its Recovery Asset Team exists to pass the transaction details to the receiving bank and ask it to freeze the account, which only works if the report is made quickly. The Bureau's own guidance to victims is to contact the originating institution as soon as the fraud is recognized and ask for a recall or reversal. Investment fraud goes to the Securities and Exchange Commission and to the state securities regulator; commodity and foreign exchange fraud to the Commodity Futures Trading Commission; problems with a bank, card issuer, servicer or debt collector to the Consumer Financial Protection Bureau; and the bank or card issuer itself should be told immediately. More than one clock runs, and they do not start in the same place. The billing-error route on a credit card is measured from the statement showing the charge. The electronic-transfer rules that govern a debit card or a bank transfer instead set the consumer's liability by reference to how quickly the loss is reported after it is learned of, with a separate outer limit tied to the statement. Waiting is survivable under the first and expensive under the second.
Fraud is also a federal crime in ways that shape enforcement. Rather than a general federal fraud offense, the government usually charges the channel used: mail fraud, or wire fraud under 18 U.S.C. 1343, which reaches anyone who, having devised a scheme to defraud or to obtain money by false pretenses, transmits anything by wire in interstate or foreign commerce to execute it. Because almost every modern transaction crosses a wire, that statute reaches most schemes, and the penalties rise where a financial institution or a declared disaster is involved. This is why a case a victim thinks of as a scam is prosecuted under a heading that never mentions the word.
A typed index of the schemes covered elsewhere on this site. Investment fraud includes the Ponzi scheme, the pyramid scheme, affinity fraud, securities fraud, the pig butchering scam, advance fee fraud and the recovery room scam that targets people who have already lost money once. Impersonation fraud includes the government imposter scam, the IRS impersonation scam, the tech support scam, the grandparent scam, and the newer deepfake scam and AI voice cloning scam that give impersonation a voice and a face. Relationship and inducement fraud includes the romance scam, the charity scam, the lottery scam, the fake job scam and the overpayment scam. Fraud aimed at people already under financial pressure includes the debt relief scam, the credit repair scam, the student loan forgiveness scam and the timeshare exit scam. Account and payment fraud includes check fraud, card skimming, account takeover, the direct deposit switch scam and phishing as the technique that enables most of them. And some fraud is committed against a system rather than a consumer, which is where insurance fraud, tax scams and property deed fraud sit. Identity theft and elder financial abuse are large enough subjects to have their own entries.