Invoices for work being billed by the hour are sent by email monthly and are due upon receipt. Thereafter, you have a 14-day period to discuss any charges you feel be inaccurate. After the 14-day period has expired, any undisputed charges will be debited from your retainer. The following month's invoice will reflect any debits from the prior month.
Invoices for work being billed on a flat rate or subscription plan are sent by email monthly and are due within 30 days.