I heard a pretty interesting story from a very experienced consultant few weeks ago. He was a consultant (development) for a mid-size client and did much of the work off site. Every week like a good consultant he turned in his timesheet and went about his business.
As the project progressed and the product got closer to completion (basics functionality was done, advanced features were missing), the pay checks stopped. Giving the client the benefit of doubt, he continued to develop and fix bugs, until the client was almost two weeks behind on pay checks.
He started to notice that the client was no longer responding to his emails or phone calls and fearing the worst, he stopped the development work until the money was paid. He tried to bargain with the client, threatening to withhold uncommitted advanced features in the development branch unless at least partial payment was made. However, he had no luck with the client and eventually decided to take the matter to small claims court.
Unfortunately the court ruled against the consultant and he lost over $20,000. Why? All because the consultant never made sure to get acknowledgement from the client for the submitted timesheets. Since he was submitting these timesheets over email, there were no signature involved. The consultant made the expensive mistake of assuming that simply because there was no acknowledgement from the client, everything was kosher.
The lesson here is to always get proof of acknowledgement from the client. If you are submitting timesheets using hard copies, then make a copy with the clients signature prior to turning in the timesheet. If you are submitting the timesheets via email or some other digital format, make sure you get confirmation from the client.