How do I check if a broker or adviser is registered?
Before handing money to anyone who calls themselves a broker, a financial adviser, or an investment professional, the 
SEC's Investor.gov recommends running that person's name and their firm's name through the free public databases the government maintains for exactly this purpose. Brokers are checked through FINRA BrokerCheck, investment advisers through the Investment Adviser Public Disclosure database (IAPD), and a single search that starts at Investor.gov will route to the right one automatically. These tools are free, require no account, and show not just whether someone is licensed but their employment history, exams passed, and any disciplinary record. Unlicensed or unregistered people commit a large share of investment fraud in the United States, which is precisely why this check matters before money changes hands, and it is a check, not investment advice about what to buy.
Where to look, and why there are two systems
Brokers — people or firms who buy and sell securities for customers, often for a commission — generally have to register with the SEC and join FINRA, the industry's self-regulatory organization. Their license and history are searchable in BrokerCheck by name, firm name, or CRD registration number. Investment advisers — people or firms paid to give ongoing advice about securities — are regulated either by the SEC or by state securities regulators depending on how much money they manage, and their filings live in IAPD. As a rule of thumb, advisers managing less than $25 million in regulatory assets under management generally register with states, those with $25 million to $100 million fall in a middle band that can go either way, and those above $100 million generally register with the SEC, as Investor.gov explains. Because someone can be a broker, an adviser, or both, Investor.gov's search is built to check both databases from one entry point and hand off to BrokerCheck automatically when needed.
What the search actually shows
For an individual, BrokerCheck reports the person's current employer, a ten-year employment history both inside and outside the brokerage industry, every license and registration held, and which qualification exams they've passed, according to Investor.gov's guide to using BrokerCheck. It also discloses criminal felony charges, investment-related misdemeanors, industry discipline or open regulatory investigations, investment-related civil actions, consumer complaints, arbitrations or lawsuits, unpaid judgments or liens, bankruptcies, and any firing tied to alleged misconduct or a failure to supervise. FINRA separately runs Disciplinary Actions Online, searchable by name, case number, date range, or CRD number, covering eligible cases dating back to 2006. For advisers, IAPD pulls the firm's current Form ADV filing — including the relationship summary, registration status, and a link to the required Part 2 brochure describing fees, practices, and conflicts of interest — plus a rundown of the individual representative's professional background and any conduct issues, as described on Investor.gov's IAPD page. A separate 
SEC Action Lookup for individuals can turn up SEC enforcement actions that predate or supplement what shows in either database.
What to do with the results, and what to do if something looks wrong
A clean search isn't the end of the diligence; Investor.gov also suggests comparing the services, fees, and compensation structure a broker or adviser offers, reading the account agreement and the firm's relationship summary, and, for advisers, requesting the current Form ADV brochure and asking directly about any discipline or client lawsuits. It's also worth contacting the relevant state securities regulator for state-registered advisers or additional state-level complaint history that federal databases might not capture. If a name doesn't turn up anywhere, or if the results reveal signs of fraud — someone impersonating a real professional, an unregistered offering, or a scheme promising guaranteed high returns — that can be reported directly to the SEC through its tips, complaints, and referrals (TCR) system, or by calling the SEC's investor assistance line at 1-800-SEC-0330. Anyone unsure where to start should begin with the single search box at Investor.gov's "Check Out Your Investment Professional" page — it's the fastest way to find out who, if anyone, is actually watching over the person asking for their money.