The commercial invoice is sent to your user ID once your order is shipped. Please check if the email is in your spam mail or blocked mail.
Alternatively, you may download your commercial invoice from the user center.
Kindly login to your Bitmain account> User Center > Sales Order > Shipped > View the order you wish to retrieve your invoice
After clicking view > Download your invoice by clicking the icon below.
NOTE: If your order was shipped a while ago (e.g. in 2017), you may not be able to find your commercial invoice in the user center. To retrieve the invoice(s), please send us a ticket indicating the order ID(s).