Thanks for your response. However, the issue is, in the TurboTax form, they are validating if the entered Document ID is "alphanumeric" whereas my Document ID is only "numeric". Therefore, it is giving error message on the TurboTax UI (form) itself to enter the correct Document ID, and not proceeding to connect to TD Ameritrade. Thus, it looks like a validation problem on the TurboTax UI.