My customers can't Split payments between two credit cards for online payments. The Allow partial payments toggle likely isn't enabled. If you don't see the toggle, please contact fintechsupport@servicetitan.com.
Split determines how much credit each technician is getting for the job. For example: If two technicians perform work on a job, the split could be an even 50%-50%, or it could be 75%-25% if the first technician did a bulk of the work.
By default 100% of the technician split will go to the first technician assigned to the job.