Resources
What we have learned matching millions of invoice lines to contract prices. No gated whitepapers — the useful part is on the page.
Why supplier invoice lines don't match your contract — the full taxonomy
Every unmatched invoice line has a reason. Here is the taxonomy — missing SKU, expired price, wrong unit, substitution, freight and more — and what to do about each.
8 min read
Unit-of-measure normalization: the quiet source of fake variances
Per square, bundle, thousand, or roll. How unit-of-measure mismatches create false overcharges, and how to build an alias table that fixes it.
6 min read
Standing, quoted, or isolated: classifying the discount you actually got
Not every price below contract is a win. How to tell a standing discount from a one-off quote or an isolated keying error — and why the difference changes what you negotiate.
6 min read
Credit and rebill pairing: the correction that reads as two errors
A supplier correction arrives as a credit plus a replacement invoice. Audited naively it looks like a large overcharge and a large undercharge. How to pair them.
7 min read
SKU stemming and family matching: rescuing the unknown-item pile
Most 'unknown SKU' lines are contracted items wearing a different code. How stemming, family matching and a confirmed alias table cut the unmatched pile.
7 min read
The three-way match gap: why matched invoices still overbill you
Purchase order, receipt, invoice. A clean three-way match confirms quantity and item but never the contracted price. What to add without slowing AP down.
6 min read
Building supplier scorecards from variance history
Variance data is a negotiating instrument. The four metrics that belong on a supplier scorecard, how to normalize them, and how to use them at renewal.
6 min read
Teardown: what an audit of $1.26M in materials invoices actually found
A line-by-line teardown of a real three-month materials audit: 3,589 invoice lines, $1.26M of spend, $14,896 of overcharges, and what the 1,751 unmatched lines were really telling us.
7 min read
Guides and free tools
- Supplier invoice price discrepanciesWhere off-contract billing comes from and how to recover it.
- Audit checklistSeven steps from raw supplier files to a documented claim.
- When a supplier won't creditThe escalation path, and the four objections you will hear.
- GlossaryEvery term this product runs on, defined in plain language.
- What an invoice price audit findsThe errors that pass every AP check, and how to size them.
- Contract price complianceHow dated matching, UoM normalization and claims fit together.
- Spreadsheet audit vs. an engineWhere a VLOOKUP audit works, and exactly where it breaks.
- Manual AP review vs. automationWhy a clean three-way match still lets overbilling through.
- Overbilling calculatorEstimate annual leakage from spend, error rate and coverage.
- Price list column mapperPaste a header row and see what an audit engine can read.