You can't call it a "contract programming" situation if there is no contract. What you are admitting to is quoting a price in haste (to get the job?) and getti

You can't call it a "contract programming" situation if there is no contract. What you are admitting to is quoting a price in haste (to get the job?) and getting it wrong. I would never provide a quote until the client has provided a specification. If they can't produce a spec, then I write one for them on a T&M basis and suggest that the client invites others as well to quote on doing the job. The spec then becomes part of the contract. What the client does with your program once completed should be of no concern to you. You wrote it for them and it's theirs to use or not use as they please. As ninjaa points out, you may or may not have intellectual property rights to the program depending on the jurisdiction in which the agreement was reached. If you accept no money and reneg, then your client doesn't have much to grouse about except for the wasted time. It's obvious that your client wasn't being professional either since they didn't demand a written contract. You could probably both put this episode behind you and chalk it up to experience.