Time & materials invoice audit
T&M invoice audits that check every line, not a sample.
Overtrace audits a contractor’s whole time-and-materials package — invoice, billing detail, field-signed T&M, sign-in sheets, equipment lists & receipts — against what was signed in the field and agreed in the contract. Every exception is cited to its page, so you can stand behind every dollar you dispute and every dollar you pass.
The problem
A T&M invoice is a few pages of totals sitting on top of a few thousand pages of proof.
Nobody checks every line.
There isn’t time. So the reviewer spot-checks, assumes the column of 10s was footed correctly, and hopes the auditor on the other side does the same.
The records never agree.
The sign-in sheet, the contractor’s own form and the T&M you signed each say something slightly different — and the names are spelled three ways.
Excel only adds what it’s told to.
Summary sheets grab the wrong column, extensions don’t multiply, and the only way to find out is forensic math, late at night, every month.
The solution
Every billed hour, rate, machine & receipt, checked against its source.
Hours against the field-signed T&M
Each employee-day billed is matched to the signed T&M, the sign-in sheet & the manpower report — with the field-signed record as the golden standard.
Rates against the contract
Labor, equipment, hauling, per diem & PPE rates are checked against the agreed schedule, including classifications billed above the trade recorded in the field.
Overtime & premium rules
Overtime before 40 straight-time hours a week, Sunday premium on a weekday, unpaid lunches billed, admin staff at premium time — caught on every employee, every day.
Receipts against billed cost
Each material line is traced to its receipt: missing receipts, costs above the receipt, duplicate invoice numbers, tax marked up & unallowable purchases.
Math, footed & cross-footed
Extensions, daily totals and summary rows are recomputed, so an error in the contractor’s spreadsheet becomes a line item instead of a hunch.
Already billed last month
Receipts and employee-days are checked across invoices, so arrears and resubmissions aren’t paid twice.
Questions
Common questions.
What is a T&M invoice audit?
A time-and-materials (T&M) invoice audit checks that what a contractor billed — labor hours, labor rates, equipment, materials and markups — is supported by the project’s source records: field-signed T&M tickets, sign-in sheets, equipment lists, receipts and the rates in the contract. Overtrace does this for every line of the package rather than a sample.
What documents does Overtrace need?
The contractor’s monthly package as a single PDF — invoice, billing detail, field paperwork and receipts, however they arrive. Optionally, the contract or rate schedule, and any past outside audit of the same contractor, which Overtrace turns into rules.
Can it read handwritten timesheets and scanned receipts?
Yes. Typed billing sheets are parsed directly; scanned pages, handwritten sign-in sheets and photographed receipts are read by AI vision. Names are matched even when they’re misspelled, reversed or abbreviated. Any finding that depends on handwriting is marked medium confidence, and hard-to-read pages are listed so a person can look.
How do I know a finding is right?
Every finding shows the line that was billed next to the record that contradicts it, with the deciding number boxed on the page image — for example, billing detail p.144 checked against the signed T&M on p.51 — and names the rule that flagged it. Code does the matching and the math, so the same package always produces the same findings, and your decisions show which rules to trust, tune or automate.
How is Overtrace different from asking ChatGPT to check an invoice?
In three ways. It combines AI and code: AI reads every page — typed, scanned or handwritten — and deterministic code does every match and calculation, so findings are accurate and the same package always gives the same answer. It learns and remembers: your rules, contract terms and past decisions are saved, so it gets more predictable — and smarter — with every invoice, instead of starting from scratch in every chat. And it’s built for review, not blind trust: findings land in a purpose-built queue, sorted by dollars, each beside the page that proves it, so your team can check everything quickly and make every call.
How long does an audit take?
Minutes, not days. Packages of hundreds of pages are read in minutes, and before it starts, Overtrace tells you how many pages it needs to read and how long that will take.
How is Overtrace priced?
As a small percentage of the T&M value audited — well below what recovery-audit firms typically charge — billed monthly for active projects, with no annual commitment. Many teams carry it as a cost of the work. Every engagement starts with a pilot on real invoices.
Get started
Bring us your worst package.
See Overtrace audit a real T&M billing package in a 30-minute demo. Then prove it on your next two invoices in a 60-day pilot.