Deadbeat clients

Has anyone had to sue a client for payment on a successfully completed project?
What options/rights might be invoked to obtain payment when a client simply holds out?

I would find an attorney that will send them a letter demanding payment as agreed, or
"you will consider taking legal action and seek payment and damages". Or you first send
them certified/registered letter and save a few hundred dollars. If you are in the U.S., you have 3 years before you
need to take them to court. Keep all your emails and detailed dates of all phone conversations for possible need by an attorney to present to judge who will see you acted upon their promise to pay.

... I too have had this experience many times, and finally realized I need to spend more time negotiating better terms of agreement, such as asking for money in stages of development. More stages the better. #1 money shows they are serious client, and more stages and payments keep them serious. The more money you get upfront the more they are likely to finish payment. Never release your content, code until final payment. Build on your own servers and let them see it and test it, but don't let them ""take it home" until all the monies are verified in your account.

You might also start working through wwwdotgurudotcom which has extensive contract / payroll stuff.