I never send the 9465 with the return, it takes too many months before the IRS responds and sends the letter either accepting or rejecting the application.

I have the client send what they can before the due date, then wait for the first bill from IRS, once that's been received, then they can create an IRS online account and set up their own payment plan.

Ive found that if Im involved and send it with the return, the clients will constantly call me when they have questions about that payment plan, and nobody wants to get sucked into all that!  The balance due to IRS is between IRS and the taxpayer, I dont want to be involved.