M1 can make transfering another brokerage account to an M1 account super easy. To initiate a transfer, please email firstname.lastname@example.org. In the email, include a copy of your most recent brokerage statement from the brokerage account you'd like to transfer to M1. Your account will be paused until the transfer is complete, which typically takes ~5-7 business days. You will be contacted via email once the transfer has taken place.