How to validate invoice totals
Dynamite Docs, 2026-08-30
Capture the printed amounts before calculating anything
Extract the printed line amounts, subtotal, discount, shipping or freight, tax, other fees, credits, payments, grand total, and amount due. Keep missing values blank. A zero means the invoice explicitly says zero, while a blank means the field was not shown.
Preserve the currency and decimal precision printed on the document. Converting too early can hide rounding differences.
Check each line amount
Where quantity and unit price are present, calculate quantity multiplied by unit price. Apply a line discount and line tax only when the invoice shows how they work. Compare the result with the printed line amount.
Do not assume every invoice uses the same formula. Some line totals include tax, some exclude it, and some suppliers round at the line level.
Rebuild the subtotal
Add the extracted line amounts that belong to the goods or services section. Exclude summary rows, carried-forward totals, deposits, and the grand total. Compare the calculated sum with the printed subtotal.
If the difference equals one full line amount, look for a missing or duplicated row. A small difference often points to rounding or a discount that was applied before tax.
Reconcile the grand total and amount due
Starting from the printed subtotal, apply printed discounts, freight, tax, fees, rounding adjustments, credits, and prior payments in the order the invoice describes. Compare that result with the printed grand total and amount due.
Grand total and amount due are not always the same. A deposit, credit note, or prior payment can reduce the balance without changing the original invoice total.
Use tolerances carefully
Define a documented tolerance that matches the currency and accounting policy. Do not use a generous tolerance to make recurring extraction errors disappear. Store the actual difference and the reason a reviewer accepted it.
Turn mismatches into review tasks
Dynamite Docs extracts the invoice fields and runs arithmetic checks on the result. When a line or total does not reconcile, the review screen keeps the invoice beside the table so you can find the wrong cell quickly.
Approve the invoice only after the printed and calculated amounts agree or a reviewer records the reason for the difference. Then export the clean rows or send the completed result through a webhook.
Related workflow: Accounts payable automation without template setup.
Try it yourself. Upload a PDF, scan, or image and let Dynamite Docs infer the schema.