As an ERO, you are using the Practitioner PIN to sign this return.  The EFIN and Practitioner PIN that you placed in the e-File Submitter Settings dialog, and Taxpayer PIN shown below in the Signature Details will all be used to provide a valid signature to the IRS.  The 5 digit PIN below can be provided to you by the customer and can be reused for each filing.


Please note that if you have a balance due and it is eligible for Electronic Funds Withdrawal, you would click the EFW button and add the account type, routing number and account number to send the balance due amount with the return.  This will only allow you to pay a balance due, and will not allow separate deposits.