At selling you need to submit an application on Treasury Direct first. But you do not need to go to a bank to do this.
Website is tricky to use. Also account security is very high - meaning you can easily get your account locked. Once that happened, the only way to unlock it is to call. Current time it is very very long wait because suddenly a lot of people are interested in the I Bonds due to the historically high interest rate. Current 6 months is 7.12%, Next 6 months is 9.62%.
Because whether you buy it on the first of the month versus the end of the month, it will count as a full month - therefore the closer to the end of the month, the busier the phone support.
Today is Apr 27, if you want to take advantage of the end of the month, you need to set up your account online tomorrow and execute the purchase before 2pm or earlier (forgot the cut off), so you transaction will be executed in time.
For unknown reasons some people's account opening process involved more verification (have to have Notarized paper from a bank then email in the support), some people can just open the account online without any extra. No way to tell.
IF you plan to do it for each eligible person in your household, you need to use DIFFERENT EMAIL ADDRESS for each person. Else you will encounter extra verification to open account.
Once your account is successfully opened, you will get an email with your Treasury Direct Account Number. That is important - because you will need this number to log in your account.
Also make sure you either do a screen shot or write down the answers for the 3 security questions you chose. I got my account locked because I forgot one answer.
