Often, creative partners delay doing so for a host of reasons, some of which are actually the best reasons to formalize an agreement:

“We’re best friends, so we don’t need a written agreement.” Sadly, a creative project gone awry can bring an end to even long-term friendships. When trust is broken, or when one person feels taken advantage of, the hurt may not only be financial or professional, but also emotional.

“We’ll set up our own agreement once we know whether a publisher is interested.” Another path to conflict, and a way to put a project in limbo. What happens when one author believes that all the income will be shared 50-50, and the other author believes he’s entitled to a larger share of income? Top billing? Sole credit? Discussing these and other issues openly at the start of a project, and memorializing what’s agreed, can make later disagreements more unlikely.

“We never agreed to call ourselves coauthors, so we’re not.” Depending on the circumstances of your collaboration, you may not have the law on your side. Joint authorship is defined in the U.S. Copyright Act, and there is a hefty body of case law that elaborates of what elements create joint authorship. Don’t assume that your definition of coauthorship is the one that will hold up in court should a dispute reach that point.

These are just a few of the situations that arise all too often.

One problem that is often not considered is what happens when a coauthor becomes unavailable. Illness, death, or other events can profoundly affect the working relationship. (Less likely–but not impossible: Your coauthor is alleged to be involved in a murder for hire. And you’re not writing a literary work about crime…)