What this does, and what it refuses to do
Tiers are marginal
A plan paying 5% below $20,000 and 8% above it pays 8% on the amount above the threshold, not on the whole deal. On a $30,000 deal that is $1,800, not $2,400. The working shows both bands separately, so the difference is visible rather than asserted.
A row it cannot read is reported, never treated as zero
A zero silently removes money from somebody's pay and reads as "this rep earned nothing" instead of "this line could not be parsed". Every rejection carries its line number, what was pasted, and the reason.
A conflicting plan is refused
If two tier thresholds overlap or descend, nothing is calculated and the conflict is named. Picking an order would produce a figure that changes depending on which order was picked, and nobody could tell from the output which one it was.
Similar names are flagged, never merged
Ana Lopez and ana lopez are reported as possibly one person and
left as two. Only someone who knows the team can say — and a tool that merged them would be
quietly moving a commission from one row to another.
Money is never a floating-point number
Every amount is an integer number of cents. 0.1 + 0.2 is not 0.3
in binary floating point, and a run that is a hundredth of a cent out is a payroll dispute.
Apportioned deal lines sum exactly to the rep's total, with no lost cent.
Nothing leaves your browser
The calculation is JavaScript running on this page. There is no account, no upload and no storage — reload and the deals are gone. A shared plan link carries the plan only, never the deals. See what is stored for the detail.