I work as an hourly employee. I have several side jobs within the same company that I do on my own time - separate from my hourly job.
To avoid OT and confusion, I received an EIN# and business name. My company is saying these 2 are not separate and they cannot pay me under the EIN# because I am an employee. Aren't the 2 completely separate?

I assume then if they can't pay you under the EIN# that they are instead going to pay you OT for each hour of your time over your current contract of employment , if not it sounds like you've been screwed by your firm mate threaten to sue the ers for exploitation if you COE states you will be paid for each hour you work and not a salary for your job because even if your secondary job is not in your primary job description you ll have a hard job proving that is the case

If you are an employee, and work for the same company then you are one employee and any work is still work for that same company, they can't pay you separate pay checks and accounts, ( I am sure this is illegal on many fronts)

You could work other jobs as a contract labor or a 1099 worker if these jobs would meet those rules,