The treasury department sent all four quarterly tax checks to the bank even though they were post dated as instructed. How do I get my money back?

[Carl]

You don't. I'm rather surprised your bank would accept a post dated check. More than likely the checks were converted to ACH withdrawals. But overall, you can consider all estimated payments for 2018 to be done with. The IRS is not going to "hold" a check per any instructions of anyone. You send them the check, they cash it. If they can't cash it, they send it back along with a bill which will include a charge for their inability to cash it. Usually, such a charge is for a bounced check because their were insufficient funds in the account. It's referred to as an NSF (Non-sufficient Funds) fee or returned check fee.

[Critter]

Good god ... why would you ever pay the quarterly taxes early ?   There were due dates on the forms for a reason and nowhere does it tell you to send post dated checks.  Hard lesson learned the hard way.

[Lisa995]

Dates on checks are meaningless....at least youre all paid up for 2018!