A partial refund, traced to the original item

Find the item that was partly reversed

Record the original invoice and item reference, staff attribution, category, date, amount, supplied tax and original calculation rate. Then record the refund reference and date. A short invoice can still contain several rates, so matching only the invoice total may be too broad.

Check whether the refund is already represented in the chosen export. Some source records may show a signed adjustment while another view shows a revised net sale. Determine the actual representation in your files before subtracting anything a second time.

Work a 30% partial refund through the same basis

This fictional AUD service originally cost $220.00 with $20.00 supplied tax. The recorded example uses an exclusive basis and a 40% commission rate. A later refund is $66.00 with $6.00 supplied tax: 30% of the original amounts.

Do not apply the item’s percentage to the whole basket

If the same invoice also includes a $33.00 retail item, the invoice total is $253.00. Refunding 30% of the $220.00 service is $66.00; refunding 30% of the whole invoice is $75.90. Those are different events and may also involve different commission rates.

Use the actual refunded line amount when it is available. A percentage is a useful cross-check, but it should not replace the source amount or invent an allocation across unrelated items. If the refund covers several categories, obtain an allocation before calculating category-specific adjustments.

Check earlier refunds before accepting this one

List all refund records linked to the same original item. In the example, a previous $66.00 refund and a new $66.00 refund total $132.00, or 60% of the original $220.00. A third request for $110.00 would take cumulative refunds to $242.00, above the original amount, and needs investigation.

An excess can indicate a duplicate refund export, the wrong original item, an additional goodwill adjustment or another source event. Do not silently cap the value or assume the difference is harmless. Keep the evidence and resolve what the source records actually represent.

Write a note that preserves the decision boundary

For the fictional example, a useful note is: “F-910 links to service S-900; $66.00 inclusive refund with $6.00 tax, exclusive basis −$60.00, original 40% rate, calculated adjustment −$24.00; cumulative refund 30%.” This is evidence for a review, not a statement that a deduction is legally permitted.

1. Identify the original item and every linked refund reference.
2. State the signed refund amount, tax amount or explicit basis assumption.
3. Record the rate used and whether it matches the original calculation.
4. Show the resulting arithmetic adjustment and cumulative refunded portion.
5. Identify the reviewed period and the reason for the accepted treatment.

Carry a reviewed adjustment into the correct period

If the original sale belongs to a completed period, preserve that record and document the later refund separately. Do not rewrite the historical service amount to make the current refund disappear. The linked records should explain both what was known then and what changed later.

Trimsum flags negative sale rows for review and calculates their signed effect using the supplied basis and applicable flat rate. It does not authorise deductions, decide refund policy or automatically recover an earlier rate from an original transaction. Confirm those inputs before accepting the result.