just the 1040-V and payment. follow the instructions for the info that needs to be on the check so it is applied to your a/c. mailing will result in further delay which may increase the penalties and interest for late payment. send by a method where you get proof of delivery. there have been some horror stories lately of undelivered mailed by the USPS. in addition, the USPS postmaster general has ordered workers not to work overtime to deliver the mail.
