For Quantity Surveyors · Cost Controllers · Commercial QS

Your batch, every line audited.

End-of-month batch of 1,000 invoices. You sample-check 50, sign off, hope nothing slipped. A workforce audits every line, cross-references site reports, drafts the dispute notice. In 4 hours.

A QS desk: invoice stacks and BOQ printout on the left, Vonbuild's line-by-line audit dashboard on the right

Left — the 50 invoices you sample-check · Right — the 1,000 Vonbuild verifies line-by-line

Today vs tomorrow

Sampling today. Auditing tomorrow.

Today

1,000 invoices. 50 sampled. €180K slipped through.

25th of the month. The batch lands. You open Excel, sample-check the top 50 lines, sign off the lot. Three months later the auditor catches a 12% overbill on a line you didn't check. You explain to the project director why the firm just absorbed €180K. Money owed. Never recovered.
Industry benchmark: 3-5% overbilling routinely on construction invoicing. Sampling misses it.
With Vonbuild

1,000 invoices. 1,000 workers. Every line, every time.

Vonbuild isn't a chatbot. It's a factory. When 1,000 invoices land, 1,000 workers spawn — each cross-references the BOQ line, the rate, the site measurement, the delivery slip. 47 anomalies flagged with evidence in 4 hours. The €180K stays in the firm.
25th becomes the easiest day of the month. You manage exceptions, not routine.
The cross-functional superpower

You don't get an invoice scanner. You get the full audit team.

Overbilling isn't just a math problem. It's BOQ math + site reality + contractual right to withhold. Vonbuild runs all three Masters on one batch.
01
Master Procurement

Audits 1,000 lines against BOQ.

End-of-month batch lands. Procurement spawns 1,000 workers — one per invoice line. Each cross-references the BOQ line, validates the rate against contract, checks the claimed quantity against the Schedule of Rates. Flags rate-drift, qty-overstatement, scope-creep. Trigger: 9am 25th.
02
Master Operations

Did they actually pour that concrete?

Procurement calls Operations. Operations pulls the site daily reports, delivery slips, pour logs for the relevant period. Cross-references the claimed 247 m³ against the site-measured 229 m³. Returns the discrepancy with evidence. Elapsed: 2 hours.
03
Master Legal

Drafts the Formal Notice citing CCAG Art 50.

Legal takes the flagged anomalies. For each confirmed overbill, drafts the Formal Notice — withhold + dispute request — citing the exact contractual right and the evidence pack. Elapsed: 4 hours total. 47 anomalies, 47 notices ready to send.
Result · 4 hours across 3 Masters
vs. 1 week of sample-based sign-off

Every line audited. Every anomaly evidenced. Every dispute drafted.

BOQ audit (Procurement) + site reality check (Operations) + dispute notice (Legal) — assembled into one defensible batch. 3.7% overbilling documented · €184K recoverable. You spend the morning reviewing the flags, signing off the clean lines, and approving the dispute notices. The €180K stays in the firm.

Live process · Procurement cascade

You ask Procurement. Five agents react. One audit trail.

An invoice lands in OneDrive. Master Procurement spawns five reconciliation agents in parallel. Match, scan, audit, draft a PO — under two minutes, evidence chain attached. Stock follow-up scheduled at delivery.

Signal

An invoice lands in OneDrive at 14:32.

Any source can fire it: a file dropped in OneDrive / Google Drive / any drive, an email landing in Outlook, a scheduled task firing, or you pressing a button. In this scenario, an event arrives via ONEDRIVE.

Source: ONEDRIVE · invoice-aluFacades-441.pdf
Routing

MASTER PROCUREMENT routes.

It classifies the impact across 21 semantic categories and dispatches to the 5 specialized agents concerned. No human in the loop. No meeting scheduled.

5 specialized agents dispatched · 312 ms
Parallel reaction

5 specialized agents. In parallel.

Each agent accesses its own toolset — apps, browsers, MCP connectors, project documents and company knowledge — and produces a structured output. Concurrently, not sequentially.

AGENT
Invoice Reconciler
€428,300
matched against PO
AGENT
Supplier Scanner
4 quotes
Δ €18.2k vs baseline
AGENT
PO Generator
PO-2026-441
purchase order drafted
AGENT
Discrepancy Auditor
1 overbill
€3,840 flagged
AGENT
Stock Tracker
S355 LV-3
12 t in transit
5 outputs produced
Convergence

Outputs return. One narrative.

The 5 specialized agents return their outputs to MASTER PROCUREMENT. It reconciles them into a single decision card.

1 reconciled decision
Validation

Handed to you. One click.

Master Procurement returns the reconciliation. Invoice matched against PO, alternatives scanned, discrepancies flagged, PO drafted, stock tracked through delivery. Full evidence chain. One trace ID. Ready to post.

3 min · signal → decision
Self-scheduled trigger

T+7 DAYS LATER. The system wakes itself up.

During the parallel phase, a agent scheduled a follow-up task on its own. T+7 DAYS LATER — without you, without a meeting, without a reminder email — MASTER PROCUREMENT wakes itself, dispatches the right agent, and executes autonomously. You delegated the mental load.

T+3minT+7 DAYS LATER · auto-fired
Auto-fired · 0 human intervention
Admissible · Provable · Defensible

How to sleep at night.

You sign off the batch. You defend the withholdings. Four guarantees that hold up in front of the subcontractor, the auditor, and your director.
Guarantee 1 · No made-up numbers

Real BOQ. Real site measurement.

The agent doesn't guess quantities. It reads your BOQ, your delivery slips, your pour logs. If the data isn't there, it reports back — never invents. Every flagged anomaly traceable to source.
Guarantee 2 · The evidence chain

Source invoice. BOQ ref. Site measurement.

Every flag carries: source invoice PDF + BOQ line ref + site measurement evidence + delivery slip + recommended action. SHA-256 hashed at ingestion. Dispute-ready from line one.
Guarantee 3 · Human in the loop

The AI flags. You withhold.

The agent never sends a Formal Notice on your behalf. It assembles the flagged batch + evidence + draft notices. You review, approve, click Send. Your sign-off stands. Liability stays human.
Guarantee 4 · Tenant-resident

Your supplier data doesn't leak.

Tenant-resident inside your Microsoft 365 or Google Workspace. ERP credentials in your secret store. Supplier negotiation patterns — your most sensitive commercial data — never train foundation models.
Live demo · Guarantee 3 in motion

This is what "you withhold" looks like.

The Formal Notice for the overbill is drafted, the evidence pack attached, the subcontractor's address pre-filled. The modal blocks. Your click withholds. The AI flags; your sign-off goes in the audit log.
Works where you work

No new UI for your QS team.

Excel stays Excel. Coupa stays Coupa. SAP stays SAP. The agent drives them — your team opens the same files they always open.
Operates inside your stack
SAPOracleSageCoupa / AribaProcoreSharePointOutlook (web)Plus any software with MCP
No new UI
QS team opens the same Excel they always open. The agent has filled the anomaly columns.
Site WiFi tolerant
Ingestion runs server-side. Site teams open results when connectivity returns. No dependency on the trailer router.
ERP-ready output
Clean lines push back to SAP / Oracle in the upload format your finance team already accepts.
For your CFO conversation

How to justify Vonbuild to your board.

Don't tell your CFO you bought an AI tool. Tell them you bought a cash-recovery engine. Three bullets, ready to repeat.
Bullet 1 · Overbill recovery
3–5%
of construction invoicing

"We catch the 3-5% sampling misses."

Industry consensus: 3-5% overbilling routinely found on construction invoicing — and only line-by-line cross-referencing catches it. Sampling misses 60%+ of anomalies. With workforce: every line, every batch, every month.
Bullet 2 · Speed
1 wk → 4h
per invoice batch

"Month-end becomes a half-day, not a half-week."

Industry typical: 1 week of senior QS time per 1,000-invoice batch (sampling only). With workforce: 4 hours, every line audited. QS time freed for value-added contract work, not reconciliation.
Bullet 3 · Dispute leverage
100%
anomalies evidence-backed

"Every withhold backed by a dispute-ready evidence pack."

Subcontractors push back on every withhold. Without evidence, you cave. With workforce: every flag carries source invoice + BOQ ref + site measurement + delivery slip. Negotiation moves from "we think" to "we have evidence".
Numbers are industry benchmarks (Monograph 2025, AEC overbilling consensus). Calibrated to your firm in the demo.

Start with your next end-of-month batch.

Drop the 1,000-invoice batch you've been doing by sample. Upload your BOQ. Drop the site daily reports. See the flagged anomalies by lunch.