Card verification is a strong first-line defence against potentially fraudulent cards, and ensures that the credit card number provided is associated with a valid, open account, and charged successfully.
Braintree (the company that handles our online payments) verifies credit cards by running a $1 authorisation, and then automatically voids the charge.
The void request is sent immediately following the card verification, however there can be a delay with some banks acknowledging the request. This can result in a temporary $1 charge on your statement. Unfortunately, this is a mandatory banking requirement and it's not something we can control.
If you're concerned about a $1 verification charge on your statement, please call your bank and ask them to remove the charge. The bank can update your statement accordingly.
Alternatively, if you don't want to contact your bank, simply wait a couple of days for the void process to be completed by your bank and check your bank statement again.