Are verbal agreements binding? Depending upon what's involved, I would say more often than not, verbal agreements aren't binding in a court of law. I'm no lawyer, but let's examine. If one agrees to perform a service for another who states he is unable to afford said service, but afterward the recipient demands a change in the originally understood verbal service agreement, then no.
Oftentimes the basis for a verbal agreement is good faith because one of two parties can't afford a product or service. In recent times, I've bartered copywriting or editing services for web design, development, or CMS (content management system) help.
I recently had to deal with the ugly side of publicity, and here I am examining and reexamining myself and my intentions to perform good deeds and network with other creative souls. This analysis strips the inherent good will.
I think more artists need to take better control of their careers, which includes a thorough understanding of the legal rights in their state or country. I'd advise not to rely on phone conversations and verbal promises meant to soothe a person's fears in the heat of the moment when they're panicking about a broken heart, job loss, or being on the brink of homelessness.
I've learned my lesson: get it in writing to prevent misunderstandings, future temper tantrums, long, threatening e-mails, and text messages at all hours of the day or night. Get it in writing, even if it's on a coffee shop or restaurant napkin. Don't threaten litigation if you've previously stated you can't afford other services, because that would be tantamount to fraud or theft of services.
Invest in a Mead Composition notebook or a digital voice recorder for all important creative and business meetings. Take meeting minutes, date the entry, and mirror back to those in attendance: "What I understand is..."
Should an agreement come from the meeting, have the other person sign and date the entry until a formal contract is created and co-signed by both parties. An audio recording is easier because it would be an actual transcript of the conversation. Don't be sneaky, mind you. Ask permission to record the conversation and place the device in clear sight.
Open your eyes and ears, and pay attention to who you're speaking with, body language, and verbal ticks, if any, before going off on a tangent with unfounded legal threats that wouldn't have legs in court.