Independent Contractor Billing Question

Hi everyone,

I'm new here and have a question about billing my client.



Currently, I have a contract with a previous employer to provide backstopping support. I work remotely, from home. The work I do ebbs and flows, and is largely dependent on the needs of the internal profit centers that I support. Some days I may be swamped with work and working diligently for a full 8-hour day, other days I may have one request come through that will take only a half hour, but I will have made myself available the entire workday and been on email, rather than take on personal things, like run errands or engage in other hobbies.



The department I work for has assigned me as the backstopper for several profit centers, so it is up to me to keep an eye out for requests from these centers and respond when those requests come in. I am not waiting on my direct supervisor to assign me ad hoc work.



My question is - for these slower days - can I bill a full day for being available, even if I receive few requests? Note that my contract is silent on retainers or fees for being on-call.



Thanks!