Plaid uses your phone number to streamline the process of connecting your brokerage account to My Portfolio. Having your phone number allows Plaid to remember the institutions you have previously connected.
Registering your phone number with Plaid will also streamline the process next time you link another brokerage account to My Portfolio.
Please note that your phone number is not required. You can click Continue as guest to connect your brokerage account to My Portfolio without sharing your phone number.