I am filing an extension of my 1040 personal return, and want to pay taxes by check by apr 18th deadline - what form do I use along with the check to send it to the IRS?

[user61]

What form should I send in the envelope along with the check payment when extending tax filing?

[bluedeb · Accepted solution]

You would mail in your check with a payment voucher (1040X).  Beware that all taxes owed must be paid by April 18th to avoid a penalty and interest.  You should mail your tax payment by midnight of the tax deadline date. which is Monday the 18th.

You can also e-file your returns, then go on the IRS website to make your Federal payment for taxes owed.  If you do use the IRS website, then choose to pay your taxes owed by check, that would get you through to e-file your return.  Then you can go to the IRS website for payments.

https://www.irs.gov/payments

If you owe State taxes, you can check your State's website for their payment options.

[akphoneguy]

I would strongly encourage you to make your payment online with the IRS.  In 2020, the IRS was months behind in depositing checks, some taxpayers got letters saying they owed the tax amount and penalties for not paying before the deadline.  With electronic payment you will see the money come out of your account.  Even if you mail in your return (I suggest only mailing if you have no other choice.).  You can set up an account with the IRS and pay thru' that platform, but you can also pay without an account.