
You must contact them
using the email address associated with your AdSense account that you
wish to cancel.
The ad code will stop
working, so make sure you've removed the AdSense ad code from all your
pages.
If your account balance
is greater than the cancellation threshold, make sure that all holds
are removed and your account is eligible to receive payments.
If you want to participate in AdSense again in the future, you'll need
to submit a new application using an email address not associated with
any previous AdSense account.