My invoices state "Due upon Receipt".  In addition, there is a notice at the bottom stating that if the invoice payment is not received within 30 days of the date of the invoice, a service/delinquency charge of 1.5% per month or 18% per year will be levied.  If it is not paid within that time, I e-mail a new invoice with the delinquency charge added. 

If I do not receive payment within 60 days for the full amount, including delinquency charge, I start collection proceedings.  If the client is an attorney, I report him to the Bar in the state in which he practices.  I have not had the occasion to report any to this Board, due to the fact that my reporting to the Bar does it.  I will say, that I will not accept work from anyone but attorneys.

Donna