Check the person
- Profile age, ratings and other listings. Brand-new profiles with no history deserve more caution.
- A reverse phone lookup: a real local mobile number is a good sign; an app number is not proof of anything but tells you less.
- Their name in a social media search.
Look up their number
Carrier, line type and location are free. Private: nobody is notified.
Scams to refuse
- Overpayment and fake checks: a buyer sends more than the price and asks you to refund the difference. The check bounces weeks later (FTC).
- "Read me the code": a buyer asks for a verification code to "prove you are real". That is the Google Voice scam.
- Shipping and "agent pickup" for local items.
- Payment-app "business account" upgrades that require you to pay first.
Meet safely
- Use a police station "safe exchange zone" or a busy store lobby, in daylight.
- Bring someone. Tell a friend the plan.
- For cars: run the VIN through NMVTIS for title brands and salvage history, and have a mechanic inspect it.