I have already received back notification (from both Fed & State) that my submitted returns were accepted. Unfortunately, my check (for owed-taxes) was sent along with the extension-application-voucher (to that address, payable to US Treasury) instead of with the submitted-payment-voucher (to a different address, payable to IRS). Should I put stop-payment on the 'extension-check' and submit another submitted-payment-check?
No, you do not need to put a stop payment on your check. It is okay that your payment was sent with your extension and not the payment voucher. The payment will still be credited to your 2018 Tax Return and since you mailed it yesterday, is considered paid by the deadline.
No, you do not need to put a stop payment on your check. It is okay that your payment was sent with your extension and not the payment voucher. The payment will still be credited to your 2018 Tax Return and since you mailed it yesterday, is considered paid by the deadline.