Rest assured, we only charge you for the transaction you meant to place.
The additional/multiple charges you might see on your credit card or bank statement are most likely your bank or credit card issuer placing a hold on funds, during the authorization process, before the actual transaction went through. In some cases, the tax amount is updated slightly between the original authorization and the actual transaction, so it will look like more than one charge.
Typically banks and credit cards release these pre-authorization funds within 1-2 business days. You can check with your bank to confirm this.
If an erroneous charge remains after a few business days, please reach out to us and we can look up your account to be sure no extra charges show up on our end.