I need advice on how best to make a contract. We have a ready-made mobile application (on which we have been worked for about a year) and the customer needs this application. Suppose its value is $ 10,000. The fact that the customer draws up a deposit through the upwork for the full amount is understandable.
What part of this amount can be made as a prepayment before starting work? Can it be the full amount? Because receiving payment after sending the full source code does not suit us, because the customer may begin to invent various pseudo reasons in order not to confirm the work done, and the source code on which we have been working for a year, it will be already owned by him. In this case, the dispute will be considered by the upwork commission (we have never had such experience) and I don't know exactly which side she will take.
Plus, it does not make sense to divide the task into milestone because the application is already ready and this will only require additional efforts to divide the application into separate working parts.
(The problem is that we can transfer the source code only when payment has already been received on our account.)
Thanks in advance for your help.
Since the work is already completed, I see no reason you can't have a single milestone, which is the client accepting your offer and releasing payment immediately after funding, at which point you will deliver the product. If there is any small amount of work such as training for you to be done after delivery of the product, you might want to have a small second milestone so the client has some comfort you won't just delivery the product then be unavailable for any follow-up.
I have occasionally required new clients who insisted they were in a big hurry to start a relatively small contract to fund escrow in full upfront, pay me 50% of the total value of the project immediately under a first milestone and release the remainder of the total due on delivery of the product.