I can copy and paste my account number into the first account number field.

Why not make it possible for me to copy and paste my account number into the second account number field?

Let me paste the confirmation account number, you morons!

I repeatedly entered wrong information because I was not able to copy and paste my account/routing number which has the same digit repeated several times. Why invite mistakes for no reason?

You allow me to paste my bank routing number in the first field but not the second... VERY FRUSTRATING!

Account number confirmation field should allow pasting. I don't understand what you are trying to prevent. If I'm copying from a password bank I'm less likely to make a mistake by pasting. Both fields have to match anyway, so if I paste into the first account field and the second one doesn't allow pasting, I'll just have to copy it manually from the first field. Not sure what you are trying to prevent - just more cumbersome for user. Great, simple interface otherwise!

Allow the user to copy+paste the account number into both fields (rather than just the first). Enhances accuracy and is better UX

change field names to accomidate auto-fill from password managers (e.g. LastPss)

Under the autopay amount have a second option that says: "Pay another amount". This info is present but not clearly shown top of the page.

Have payment info formatted to be typed in by an iPhone. Not rocket science.

Add a line for a tip

Account number confirmation field should allow pasting. I don't understand what you are trying to prevent. If I'm copying from a password bank I'm less likely to make a mistake by pasting. Both fields have to match anyway, so if I paste into the first account field and the second one doesn't allow pasting, I'll just have to copy it manually from the first field. Not sure what you are trying to prevent - just more cumbersome for user. Great, simple interface otherwise!

Let me CORRECT my credit card number using my cursor to move, enter & delete, instead of appending new digits to the end of the field.

Don't have the payment page automatically launch the invoice. It breaks some browsers because you can't stay on the payment page. For example, Vivaldi (a privacy-oriented Chrome variant).

make the font on the receipt smaller so that receipt is only one page, not two.

Act on the 206 suggestions and numerous votes for a Memo/Notes line on the payment form.

Allow memo section so if you want to make two payments or pay ahead then you can note that in the memo.

Create a third option after paying an invoice besides "Download receipt" and "Download invoice" that is "Pay another invoice". This would then take a user to their next invoice(s) to be paid.

Put the paid receipt and the invoice on one page so I don't have to print two separate documents

Would you please send the itemized invoice electronically instead of leaving at door? Leave a business card or note of some kind after servicing.