I have a CP14 letter from the IRS with a "Dishonored payment penalty."

[Pax-Tayer]

TurboTax used the direct pay bank account number from last year, even though I changed it this year.

[Lisa995]

Are you sure it got changed on this years return?   Do you see the payment withdrawn from your account for the 2015 taxes?

[Pax-Tayer]

I suspect there was a UI bug that kept the old account number, and I didn't catch it. I got the failure notice on tax day and made the payment from the IRS website on time.

[Opus 17]

If there really was a bug, and you did change the account number and turbotax did not accept the change, you might have a case for the accuracy guarantee to cover the fee.  But it might be hard to prove that you tried to change the number.  See here to submit a claim,

https://ttlc.intuit.com/replies/3302050