I am a software engineer that has several clients that need me to do simple ad hoc tasks throughout the year for various projects. I have began considering setting up a retainer-based service for them where they would pay money into a retainer account for a specific project, and if I don't bill enough time to earn all of the retainer, then I would refund the unearned portion.
My concerns:
- do retainers typically go through a 3rd party the same way escrow does? or would I just manage the retainer myself in one of my own business accounts?
- can retainers be used for purchasing supplies, renting servers, purchasing licenses, "business expenses" related to the project, etc. or are they only allowed for use w.r.t. billable time?
- from a tax perspective, are there different tax rates, terms, forms, etc. that I would need to submit each year at "tax time" for operating this way (using retainers)?
- any other caveats or pitfalls I should be aware of before going down this route?