Start with the source record
Begin with the document actually issued by the supplier or business. Keep a reference to the original, record who provided it and note the period you are reviewing. A spreadsheet row without its source is difficult to investigate later.
For an internal working paper, capture the invoice identifier and date, party details, description, taxable value and tax amounts. This is a preparation checklist, not an exhaustive statement of legally required invoice particulars.
Separate data checks from tax decisions
Check whether the values add up and whether the invoice is repeated in the register. Then review the nature of supply, classification and location context separately. Correct arithmetic cannot establish correct tax treatment.
Do not choose a tax rate from an old invoice alone. Rates, applicability and invoicing rules may change. Check the currently applicable official material and record the basis used for the specific transaction.
- Flag missing or inconsistent party identifiers.
- Compare document dates with the accounting period.
- Link credit notes and other adjustments to their source record.
- Keep uncertain classification questions open for professional review.
Create an actionable exception list
A useful exception describes the issue, the evidence still needed, the person responsible and the proposed next step. For example: 'Invoice date differs between the source bill and register; obtain confirmation before changing the record.'
Resolve the source of the difference before preparing an adjustment. Preserve the original record and the explanation for any change. This makes subsequent review easier and prevents a correction from becoming an unexplained overwrite.