That's a very complicated for PHP 10,000.00 business. You might put a request tickets as well. You might end no $ because of the lawyer's fee.
In this type of business and scale (I assume that it's not big because you're doing it alone), why cant make your client as your partner? Dont feel them that they are not your friends by signing them lots of papers. Trust is the key and just be honest to your clients and charge them according to your man-hour. In this way, if they will have lots of requests, you just charge them by hours.
If it's complex, it will take time, then you charge more. Dont think about additional charge for intellicatual property because there's nothing intellectual there unless you discovered a breakthrough algorithm.

Originally Posted by
UtOkbOlinAO
it depends on the Memorandum of Agreement..
For me lang ha, dili man gud ko mohimo ug system kung walay MOA..
Ang naa sa MOA kay, ang mga conditions nga akong gi.trabaho apil na ang maintenance ug warranty good for x number of months ug ang ways sa pagbayad..
kung verbal lang gud, daghan madisgrasya ana... usa pa business is business... lisod baya pangita ug kwarta karong panahona... so, better not give the source code... pero depende rasad na nimo bro...