How can I delete my google cloud platform billing account?

I have created some billing accounts but I want to delete some as you can see in the picture, I want to delete BillingAccount1 and BillingAccount2 since Google told me that there are some issues in these accounts.

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In the documents, I did find the delete button on the system.

Why am I being charged Google cloud?

The linked payment instrument (such as a credit card or bank account) will be charged automatically when your accrued Google Cloud costs meet the threshold amount on your Cloud Billing account, or thirty days after your last automatic charge, whichever comes first.

If you want to remove the credit card which connected to your billing account, just go to: https://pay.google.com/gp/w/u/0/home/activity and remove it from there.

Dunno why Google made it so inconvenient

As per the official documentation:

Cloud Billing accounts cannot be deleted.

So, you can close the billing accounts, but those can not be deleted.

The best thing you can do is keep them closed and not use them.

I can see you still have a project linked to BillingAccount2, so you could move that project to a billing account that it's working. Other than that, not much you can do.