Strung (string) rebates¶
A strung rebate calculates on turnover that has already had another element's rebate deducted from it — it earns on net-of-rebate turnover rather than gross. Use it when two rebate elements are chained ("strung") together and the second should not pay rebate on money the first has already given back.
How it calculates¶
A strung element names one or more target elements on the same deal. Each period, for each member, the engine takes the member's turnover on the relevant stream and subtracts the rebate the target element(s) produced for that same member and period window. The element then calculates normally — banding, rates, output types all unchanged — but on the reduced figure.
The deduction can apply to either or both sides of the calculation:
| Strung on | Effect |
|---|---|
| Input stream | The band is chosen using net turnover — reaching targets gets harder |
| Output stream | The rebate is paid on net turnover — the payable shrinks |
| Both | Both of the above |
Example. Element R1 is a 2% guaranteed rebate. Element R2 is a 1% rebate strung against R1 on the output stream. A member does £100,000 in the period. R1 pays £2,000. R2 then pays 1% of £98,000 (£100,000 − £2,000) = £980 — not £1,000. Without the strung flag R2 would earn on the gross £100,000.
Because the deduction reads the target element's calculated lines, element order and recalculation matter: the strung element picks up whatever the target element most recently produced for the window. A strung element can also be catch-up, in which case it measures cumulative net turnover from the element start each period.
Why does a strung rebate change unexpectedly?¶
- The target element recalculated — anything that changes the target's payable (new turnover, band crossing, manual payment edits) flows into this element's net turnover even though nothing on this element changed.
- The strung side matters: an element strung on the input can drop a band when the target element's rebate grows, which looks like a rate cut with no turnover change.
What a strung rebate is not¶
- It is not a compound rebate. Compound reduces the final payable amount by what another element paid (a money-off-money adjustment); strung reduces the turnover being measured or paid on before the calculation happens. A compound element still banded on gross turnover; a strung element may band on net.
- It does not delete or alter the target element's own rebate — the target pays in full; only this element's view of turnover is reduced.