Each month a copy of your paid invoice is emailed to your account email on your subscription renewal date. The subject of the email is "Your YouCanBook.me payment" followed by the invoice number. Emails send from firstname.lastname@example.org so add this to your address book to ensure delivery.
You can also find copies of your invoices on your billing page in your account. Click View PDF to view or download past invoices. View on your billing page here.