Only an Administrator can access invoices from the 'Account' section of your 'Settings' area.
Click on the 'Billing and Invoices' button on the right.
The 'Billing and Invoices' page will list all of your invoices. Just click on the 'View' link to download.
Automatically email my invoices
To automatically email your invoice each month, click the 'Add Billing Address' button.
Add the email address that you would like a copy of your monthly invoice emailed to in the 'Billing email' text box and click 'Save'.