Incentive pay is any money an employer pays for a result rather than for time worked: sales commission, production bonuses, safety awards, profit sharing, piece rates and objective-based bonuses all sit inside it. The term is the employer's and payroll's word for the money itself, covering schemes that have nothing to do with selling.
Employers reach for this phrase when they are describing a payroll category. Compensation consultants reach for incentive compensation when they are describing a design. The two overlap almost entirely and the difference in emphasis is real: one names the money that has to be calculated and withheld on, the other names the thinking that decided how much it should be. A manufacturing plant paying $0.42 a unit to 200 line operators has incentive pay and, in most cases, nobody who would call it a compensation plan.
That breadth is the useful part of the term. Sales commission gets nearly all the attention and it is a minority of the incentive pay running through a typical mid-size company's payroll. Field technicians paid per completed job, drivers on a delivery rate, warehouse teams on a quarterly safety award, clinicians on relative value units, recruiters on placements, store managers on a scorecard. Every one of those needs somebody to establish that the condition was met, and the evidence for that sits in a different system from payroll in almost every case.
Where incentive pay differs from a salary line is that it arrives with a proof obligation attached. Payroll cannot release it until someone confirms the units, the installs, the attainment or the score. That confirmation is the whole administrative burden, and it explains why incentive pay across a company is frequently administered by four different people in four different spreadsheets while base salary runs through one system with an audit trail. Commish exists for the sales-shaped part of that problem, and the shape generalises further than most teams expect.
A 60-person company totals a quarter of incentive pay. Four schemes, four measurement systems, one payroll run at the end of it.
Only the first line is sales commission. The other $75,400 is incentive pay by every definition payroll uses, and in most companies it is tracked nowhere that finance can audit.
The commission plan gets a tool because the amounts are large and the reps complain loudly. The install rate, the safety award and the manager scorecard get a spreadsheet each, because individually they are small. Added together across a year they are often the larger number, and they carry the same risks: a missed payment nobody notices for a quarter, a duplicate nobody catches at all, and no record of which period a given amount belonged to when someone asks eighteen months later.
The long form lives in the guides: Sales incentive programs.
Commish pays incentive pay the way your plan describes it, shows the arithmetic on every line, and traces each payment back to the deal that earned it.