1) Until payment is due and is not made (or not made in full; partial payment will not discharge the obligation), you don't have a cause of action. You may be certain the author will default, but you don't have a claim until the payment date passes. That said, you can sometimes sue earlier if the other side has clearly repudiated the contract, but if its within 2 months of the date, it may be better to wait than file now and potentially have to refile again, if a court concludes the repudiation was not clear enough.2) Whether you can sue for the whole amount or not depends on what the contract says. If the author has to pay the $10,000 no matter what, then you can sue for the whole thing. If there are conditions under which they would not have to pay the whole $10k--i.e. they only pay based on what has been earned--then you can only sue for the whatever amount you can prove they would have to pay to you.You should probably retain an attorney to help you, given the amount at stake. You should then be guided by your lawyer's advice, after (s)he has had a chance to review the contract, all communications, and the circumstances.