Invoice discrepancy checker
Compare the total an invoice states with the total its own lines produce, and see exactly where the two diverge — with the arithmetic and the source text behind every difference.
What counts as a discrepancy
A discrepancy is simply a gap between two figures that should agree. On an invoice that usually means one of three things: the stated total does not follow from the lines, the VAT does not follow from the rate and the net, or the price charged does not follow from what was agreed.
Naming which of the three it is matters, because each has a different conversation attached to it.
Common causes
Rounding
VAT rounded on each line and VAT rounded once on the invoice total can differ by a cent or two. This is the most frequent difference and almost never an error.
Line-level mistakes
A quantity that does not match the delivery, a unit price a version behind the current rate card, or the same line entered twice. These are usually the largest differences and the ones worth querying first.
VAT errors
A reduced-rate item charged at the standard rate, VAT applied to a figure that already included tax, or two rates blended into one average instead of being grouped.
Discounts and surcharges
A discount applied after VAT instead of before it changes the tax base. Fuel, delivery or handling surcharges may be legitimate, or may be leftovers from an arrangement that has since ended.
Contract mismatches
The arithmetic can be flawless while the price itself is not the agreed one. Only a comparison against the contract or rate card surfaces that.
A worked example
An invoice states a gross total, but the lines produce a different one. Showing both makes the size and the source of the gap visible:
- Calculated net from lines
- 1,000.00
- VAT 21% on calculated net
- 210.00
- Calculated gross total
- 1,210.00
- Gross total stated on the invoice
- 1,260.00
- Difference to review
- 50.00
A gap of this size is not a rounding convention, so the next step is to find the line that explains it — and if none does, to ask the supplier.
Evidence, not accusations
Every difference is presented with the numbers it was derived from and, where a contract was supplied, the clause or rate-card row it was compared against. The wording stays cautious by design: a finding says what differs, not that you were overcharged. That keeps the output usable in a supplier conversation, where an evidenced question lands far better than an allegation.
Frequently asked questions
- What is an invoice discrepancy?
- Any difference between what an invoice states and what the underlying data supports: a total that does not match its own lines, a VAT amount that does not match the rate, or a price that differs from the agreed contract.
- Why does my invoice total not match my calculation?
- Common causes are rounding per line versus per invoice, VAT applied to a gross amount, a discount applied before or after tax, a line quantity or unit price that differs from the order, or a surcharge that is listed but not obviously labelled.
- Is a small difference always an error?
- No. A difference of a cent or two is usually a rounding convention. Larger differences, or small differences that repeat on every invoice, are the ones worth investigating.
- How do I dispute an invoice discrepancy?
- Query it in writing with the supplier, quoting the invoice number, the specific line, the amount you calculated and the agreed price or contract clause you are relying on. Keep the invoice unpaid or pay only the undisputed part while the query is open, in line with your terms.
- Does the tool decide who is right?
- No. It shows where the figures differ and what the difference is based on. The interpretation, and any dispute, remains yours.
Differences reported by ChargeAlign are indications to review, not determinations. ChargeAlign does not provide tax, accounting or legal advice; take disputes and tax questions to a qualified professional.
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