A competitive combined method (recommended)
Final Commission Rate = Base rate (by Invoice Value) + Uplift (by Age of Debt)
Then apply a sensible cap (so it never feels punitive).
1) Base commission by Invoice Value (competitive, proportional)
| Invoice Value (£) | Base Rate | Estimated Commission (£) |
|---|---|---|
| 5,000 – 10,000 | 10% | 500 – 1,000 |
| 10,000 – 20,000 | 8% | 800 – 1,600 |
| 20,000 – 30,000 | 7% | 1,400 – 2,100 |
| 30,000 – 40,000 | 6% | 1,800 – 2,400 |
| 40,000 – 50,000 | 5% | 2,000 – 2,500 |
| 50,000 – 60,000 | 4.5% | 2,250 – 2,700 |
| 60,000 – 70,000 | 4% | 2,400 – 2,800 |
| 70,000+ | 3.5% | 2,450+ |
(This keeps “higher value = lower rate” but avoids very high %s that can look uncompetitive.)
2) Uplift by Age of Debt (replaces the “age table” %s)
| Invoice Age (Days Overdue) | Add to Base Rate |
|---|---|
| Up to 30 days | +0% |
| 31 – 60 days | +1% |
| 61 – 90 days | +2% |
| 91 – 120 days | +3% |
| 121 – 180 days | +4% |
| 181 – 240 days | +5% |
| 241 – 300 days | +6% |
| Over 301 days | +8% |
3) Caps (so it’s competitive both ways)
- Cap: 20% maximum (so small debts don’t get hammered)
- Floor: 3% minimum (so large debts still justify the work)
So:
Final Rate = min(20%, max(3%, Base + Uplift))
What this looks like in practice (quick examples)
- £8,000 invoice, 75 days overdue
- Base 10% + uplift 2% = 12% → £960
- £45,000 invoice, 200 days overdue
- Base 5% + uplift 5% = 10% → £4,500
- £90,000 invoice, 330 days overdue
- Base 3.5% + uplift 8% = 11.5% → £10,350
Why this fixes your current two-table conflict
- Your age table starts very low (3–5%) and ramps to 25%.
- Your value table starts very high (20%) and drops to 3%.
Those clash (especially for newer/smaller invoices). The combined method makes them work together: value sets “fair baseline”, age adds “difficulty premium”.
If you want, I can also produce a single matrix table (Age bands down the side × Value bands across the top) showing the final % in every cell.