From the Freelancers Union blog, a great article about managing your payment terms.
Net-30 is the Voldemort of Freelance Payment Terms
by Matt Fulton
Hi. Can I borrow $5,000 to pay for your design/accounting/consulting/freelance services? I’ll pay you back in a month or two, after you’ve completed the work.
No? I didn’t think so.
Yet this is effectively what we are doing when offering clients net-30 payment terms. The only difference is that, instead of giving the client cash like with a traditional loan, we are trading dozens of work hours for the promise of future payment.