Anyone with a credit card can pay SCA online for anything at any time:

Go to www.PayPal.com.
Log in or Sign up
After logging in, Click on the “Send” button.
When asked, enter the following:
Email: Lorene@SchoolChess.org
The amount to send.
Message: Say what the payment is for, usually the player(s) name(s) & tournament name and/or date.

PayPal periodically changes it’s payment pages.  If you realize this process is no longer valid or something is missing, please let us know by sending an email to WebMaster@SchoolChess.org.