Here's how it works. Scammers target people who post things for sale on sites like Craigslist or Facebook Marketplace.If the scammer enters the code on the signup page, and the personal number used qualifies, Google issues a Google Voice number to the scammer. Fraudsters will sign their targets up for Google Voice to access their verification code and hijack the account and personal information. To prevent unwanted access to your account, it's important you don't reply to any requests for your verification code. To completely avoid a Google Voice verification scam, only do business in person with verified funds. Take your time while selling items online. Google Voice scams occur when fraudsters link a Google Voice number to your phone number. All they need is a unique verification code that they get from you. AG Nessel Amplifies BBB Warning About Using Smartphones, Devices to Look Up and Call Numbers.