IF you are using using the Browser-based Online TTX software to file..
1) As long as you don't have any "software" fees to pay, you don't need a credit card. (meaning you can remain in the "Free" version and don't have to use a higher version due to certain forms required in your tax file). IF you have to use a higher version to file (e-file or by mail-paper), and you also owe the IRS a balance due, then you will require a CCd to pay TTX for the software fees before e-filing, even if you will later be paying the IRS with a paper check in the mail.
2) Thus, if you can remain in the Free version for your tax file preparation, then you can e-file without a CCd.....and if you owe a balance due to the IRS (or state) you can indicate that you want to pay by paper-check thru the mail during the filing steps.
3) ....then you can e-file, and print out a copy of your tax file, which should include a single 1040V voucher to mail in with your check (state forms vary). The amount indicated to pay may, or may not include any late-filing penalties or interest...and even if it does, the IRS may send you a letter and charge you more later depending on "exactly" when they receive your check and open/cash it.....since the software has no way to predict the exact date the IRS actually gets your check.
4) If your tax file printout contains multiple 1040ES vouchers....those are NOT payments for your 2020 taxes...those are pre-payments against what the software "thinks" you will owe for when you file 2021 taxes next year. You can either pay those (though the first two have been missed already), or ignore them if you are fairly sure you won't have a final balance due of more than $1000 when you file at tax time next year.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
