Skavio Flow: compare invoice totals with line-item sums before export
Skavio Flow turns invoices into structured data for review and export to XLSX, CSV or JSON. But checking the extracted figures requires more than adding the rows and comparing the result with the largest number on the page. Line-net subtotals, VAT-inclusive totals and amounts due describe different things. A useful review starts by identifying which amounts should agree—and which documented adjustments explain the difference.
Compare like-for-like amounts, not just prominent totals
Flow supports custom extraction fields and saved company workflows. For recurring invoice processing, define fields with distinct meanings: currency, line-net subtotal, document-level allowances, document-level charges, total excluding VAT, VAT total, total including VAT and amount due. A single field called “total” leaves the reviewer with avoidable ambiguity. Peppol BIS Billing provides a useful arithmetic reference through the relationships below. These rules help structure a review; they do not establish that every supplier PDF follows that billing profile or that Flow performs Peppol validation.
- Line-net subtotal = the sum of individual line net amounts.
- Total excluding VAT = line-net subtotal − document-level allowances + document-level charges.
- Total including VAT = total excluding VAT + total VAT.
- Amount due = total including VAT − amount already paid + the payable rounding adjustment.
A fictional invoice shows why different totals can all be correct
Consider a fictional invoice with two net line amounts of EUR 100.00 and EUR 50.00. Their sum is EUR 150.00. A document-level discount of EUR 10.00 and a charge of EUR 5.00 bring the total excluding VAT to EUR 145.00. The invoice states VAT of EUR 29.00, producing a VAT-inclusive total of EUR 174.00. A prior payment of EUR 20.00 leaves EUR 154.00 due, with no rounding adjustment. The line sum of EUR 150.00 should therefore not equal either the gross total of EUR 174.00 or the amount due of EUR 154.00. Those differences are explained by the document, not necessarily by an extraction error. Now suppose the second line is extracted as EUR 45.00 rather than EUR 50.00. The extracted line sum becomes EUR 145.00—EUR 5.00 below the source’s line-net subtotal. Its apparent match with the total excluding VAT is coincidental: the comparison still needs to account for the document-level discount and charge. Check the second line against the original invoice. Do not change the header total or add an invented balancing row merely to make the figures agree.
Investigate the difference against the source
Flow’s verified outputs include source evidence and review warnings. Use them alongside the original document when investigating a mismatch. The comparison described here is a reviewer procedure, not a claim that Flow automatically reconciles invoices, applies configurable tolerances or blocks exports. Start with completeness: are all invoice pages present, and has every relevant row been captured once? A carried-forward subtotal should not be counted as another purchase line. Then check what the figures represent. A discount already included in a line’s net amount must not be deducted again as a document-level allowance. If a particular row is in doubt, inspect its quantity, net price, price-base quantity, line allowances and line charges. Do not assume that every line amount is simply quantity multiplied by the displayed price. Check rounding against the document and applicable billing rules rather than dismissing a small difference as harmless.
- Check for missing or duplicated rows, repeated page subtotals and incomplete scans.
- Confirm currency, decimal separators and the signs of discounts or credit amounts.
- Distinguish line-level adjustments from document-level allowances and charges.
- If the source is unreadable or internally inconsistent, record the unresolved difference rather than guessing.
Export the reviewed figures—not a forced balance
Once the comparison is understood, correct extraction errors only where the source supports the correction. If the supplier document itself appears inconsistent, keep that issue separate from an extraction mistake and resolve it before treating the data as approved for downstream accounting. Flow provides XLSX document and line-item worksheets, CSV and JSON outputs. Choose the format for the receiving workflow, then check that the exported header amounts and line items reflect the reviewed result. Keep the source document and any unresolved exception notes with the handoff; do not assume the chosen export format carries every review detail automatically. A 1 October 2026 acceptance test covered extraction and export of two synthetic PDF invoices. It also verified a scalar-field correction that regenerated results without a second job. That is limited evidence for the tested correction path, not proof of every line-item editing operation or a customer outcome. Finally, remember that arithmetic agreement is only one check. Two incorrect line values can offset each other. A balanced result still needs source review.