I efiled my federal taxes. after which I mailed in my payment for the amount I owe. However, I didn't add the 1040v payment voucher with my payment. i did, add a copy of my federal return printed from where i efiled. Is there anything I need to do to make this correct? i have tried contacting the irs helpline but was on hold for a long time

The 1040-V is a simple form which basically allows the IRS to more accurately and efficiently record your payment. You should be able to fill out your 1040-V in a matter a few minutes. However, if for some reason you fail to submit the form, you will not incur a penalty.