A tannery, constructed for this page like every figure in it, sells finished hides for US$640,000 under a sight credit requiring presentation within 14 days of shipment and expiring on 30 April. It ships on 9 April, so its last day is 23 April. Its bank has advanced 85% of the invoice at 8%, on the strength of the credit. The tannery presents on 21 April. Four banking days later, on 27 April, a notice of refusal arrives listing two faults: the invoice says finished bovine leather where the credit says full-grain bovine leather, and the insurance certificate is dated 10 April, a day after shipment, with nothing on it to show cover began by 9 April.
Both documents could be fixed in an afternoon. It does not help. The presentation window closed on 23 April, so a corrected set would now be late, which is a further discrepancy. Everything rests on the buyer, leather prices have softened, and the buyer offers to waive in return for 4% off. Payment arrives on 23 May, 26 days later than planned.
Invoice under the credit 640,000
Price reduction for the waiver, 4% (25,600)
Discrepancy fee, as the credit allowed (150)
Received 614,250
Advance: 640,000 × 85% 544,000
Extra interest: 544,000 × 8% × 26 ÷ 365 3,100
Total cost: 25,600 + 150 + 3,100 28,850
As a share of the invoice: 28,850 ÷ 640,000 4.5%
Gross margin at 12%: 640,000 × 12% 76,800
Share of that margin lost: 28,850 ÷ 76,800 38%
The price reduction and the margin are the example's. A buyer may waive for nothing, or decline. The point is the sequence. For those 26 days the bank's advance had no issuing bank behind it, only the buyer's goodwill and the tannery's own balance sheet.