Make sure they need to pay the final installment before they can have full acces to the site. In the case where you develop directly on their server, try to crypt your php code with the tool from ZEND.com But best thing is to develop on your server so they don't have access to your source files until final payment is made. That's the only way to be sure they'll want to pay fast, because they always want it delivered quickly, so tie that to their final payment If one new client has a problem with that, then it's probably not worth the trouble. You can trust them, and sometimes it'll turn out they'll pay, but if you have enough regular clients, don't bother with new ones not accepting your rules despite your explanation. cheers, -----Original Message----- Al.so, does anyomne have any advice re: ensuring small to medium sized clients pay up promptly?