Our payment processor may send a request to your issuing bank for either a $0 or a temporary $1 authorization to verify that the card is issued and the bank will allow it to be authorized
(Note: the $1 authorization always occurs for Amex cards).
This authorization is reversed immediately, but you may still see a temporary authorization for $1 on your credit card statement.
The important thing to remember is that this is not a charge, and it will disappear from your statement.
Depending on the bank, it will be removed from your statement in anywhere from a few minutes to a few weeks.