Accounts Payable with Automatic Three-Way Match
Every supplier invoice is held against the purchase order and the goods receipt before anyone looks at it. What lines up goes through; only the line that does not reaches a person – with all three documents side by side.
Reading the invoice is the easy part
Extracting an invoice is the simplest step in the whole process. Supplier, invoice number, net amount, tax, payment terms – it is all printed on the document, and with ZUGFeRD or XRechnung it is machine-readable inside it. The question that actually costs time comes next: is any of it correct? Answering it requires two documents the invoice does not bring with it.
The counter-evidence sits elsewhere – the purchase order with buying, the goods receipt at the loading bay, in the warehouse or on site. Both are created at different moments, by different people, and often beside the system: reordered by phone, delivery note left in the van, quantity signed off on a clipboard. Even when everything exists, the lines rarely align: 20 metres of cable ordered, one drum delivered, 20.4 metres plus a drum deposit invoiced. Add part deliveries, collective invoices covering three orders, and alloy, energy or small-quantity surcharges nobody ordered.
So the bottleneck is not data capture but clarification – and clarification runs against the clock. Accounting asks buying, buying asks the supplier, the site manager is on site, and the early-payment discount expires in four days. That is why we build the matching logic and the tolerances first, not the form: whatever sits inside the agreed limits needs no approval at all. Whatever sits outside goes to exactly one person, who can see immediately which line fails and why.
For that match to start reliably, the vendor must already be approved. Supplier onboarding automation first collects master data and evidence, separates sensitive review steps and hands only the approved record to the ERP.
Which invoices are worth automating
We start with the invoice type that occurs most often and has the clearest comparison data. Further types later use the same queue and the same rules.
Material invoices with an order reference
The most common starting point: order and goods receipt exist in the system, and matching runs line by line against your tolerances.
Material for sites and projects
Goods go straight to site and the delivery note is signed and photographed there. The invoice is matched to a project and job number rather than an order.
Recurring invoices without an order
Electricity, leasing, telephone, rent, insurance: there is no goods receipt here. The check runs against the contract, the previous month and the expected interval.
Interim and final applications
Each interim application is held against the amount invoiced so far and the reported stage of completion, with retention shown separately.
Subcontractor invoices
Reverse charge under section 13b, the exemption certificate under section 48b and its expiry date: if one of them is missing, nothing is approved, it is reported.
Small amounts and ad-hoc purchases
Below a value limit you set, checking costs more than the mistake it prevents. Those documents pass with a coding suggestion and are sampled rather than reviewed.
Three documents side by side, line by line
One invoice with four lines, held against the purchase order and the delivery note. Two lines go through, two do not.
| Line | Order | Delivery note | Invoice | Result |
|---|---|---|---|---|
| 10Steel beam IPE 200, 6 mItem 44-1180 | 40 pcs · €68.50 | 40 pcs | 40 pcs · €68.50 | matches |
| 20Welding wire G3Si1, 15 kgItem 71-0442 | 12 pcs · €42.00 | 12 pcs | 12 pcs · €42.90+ €0.90 per unit, + €10.80 in total | price + 2.1 % |
| 30Grating 1000 × 300Item 22-9007 | 24 pcs · €57.00 | 18 pcs6 pcs outstanding, due 4 Aug | 18 pcs · €57.00 | matches, part delivery |
| 40Freight chargeno item number | not ordered | – | €48.00 | approval needed |
Tolerance per line: at most 2 % and at most €25. Both limits have to hold. Freight and surcharges without an order reference always go for approval.
Matching rarely fails at reading the invoice. It fails at the column nobody in the business keeps up to date.
Example data from a steel fabricator. The 2 % limit is a common starting value; the tolerance that applies to you is a decision for buying, not for the software.
From the mailbox to the payment proposal
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Bring intake together
Invoices from the central mailbox, from uploads and from supplier portals enter the same queue. PDF, scan, ZUGFeRD and XRechnung are treated alike, and the original document stays untouched.
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Extract and assign
Header and line data are captured as structured values. We identify the supplier by VAT number, IBAN and creditor number rather than by name, and pull the order number from the subject line, the body text and the line items.
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Match against order and goods receipt
Quantity, unit and price of every line are held against the purchase order and the goods receipt, with part deliveries and open quantities carried forward. In parallel, duplicates are checked by invoice number, creditor, amount and date.
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Send only deviations for approval
Lines inside the tolerance count as checked. Everything else is routed by cost centre, amount and project to the responsible person – with reminders, a named deputy and escalation once the deadline passes.
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Hand over with the deadline attached
Document, checked lines, coding suggestion and audit trail move on to DATEV, the ERP or the archive. The payment proposal carries the early-payment date, not just the due date.
What changes day to day
Today
- Invoices sit in four mailboxes and one shared folder
- Accounting collects order and delivery note by hand
- Approvals run by email, with no deputy and no deadline
- The early-payment discount lapses while one line is queried
- Duplicates surface in the payment run, sometimes not at all
With automatic matching
- Every invoice arrives through one queue and is numbered
- Order, delivery note and invoice sit next to each other
- Only deviations go out, to one named person
- The payment proposal knows the discount date and days left
- Duplicates are caught and held before the handover
Where matching does not help
Four points we settle before quoting. The first is a reason not to buy this yet:
- Without purchase orders and recorded goods receipts there is no three-way match. If you order by phone and file the delivery note in a folder, the best we can give you is a well-sorted distribution to approvers – and €2,490 is not worth paying for that. Where orders are not captured systematically, purchase requisitions are the project that comes first.
- Coding and input tax stay a professional judgement. We suggest account, cost centre and tax code from how the supplier was treated in the past and write the suggestion into the target system. Responsibility stays with your accounting team and your tax adviser. Reverse charge, intra-community acquisition or the line between expense and fixed asset are not decided automatically.
- Extraction is good, not flawless. Structured formats are read in full; a creased scan with a handwritten note is not. We therefore work with confidence thresholds: anything below goes for visual checking instead of quietly running on with wrong values. Anyone expecting zero manual work will be disappointed – what is realistic is that the exceptions become few and visible.
- No software can force a fast approval. We build in reminders, deputies and escalation, but if an approval has taken two weeks for years, automation only moves where the waiting happens. What helps is a binding deputy rule and a value limit below which nobody has to approve at all. Both are management decisions, not settings in a system.
Fits your accounting stack
Scope and price
The entry price covers one intake queue, one match against one order system and one approval path. What moves the price, we say before the quote.
- One central queue for a mailbox plus uploads and portal exports
- Header and line extraction, including ZUGFeRD and XRechnung
- Supplier identification by VAT number, IBAN and creditor number
- Duplicate checking before every handover to the target system
- Three-way match against one order and goods receipt system
- One approval path by amount and cost centre, with a named deputy
- Documented rule set, handover session and 30 days of support
What increases the price
- Several legal entities with their own charts of accounts
- A second source system for orders or goods receipts
- Project references, interim applications and retention in construction
- Coding suggestions learned from past supplier behaviour
- Connecting an audit-proof archive or migrating historic documents
Several legal entities with their own charts of accounts, project references and interim applications typically sit well above this. We quote the binding fixed price after the intro call.
All prices excl. VAT · operation and further development optionally via a support package
What you get
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Production intake route
Set up from mailbox to handover and signed off with your own real invoices
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Documented rule set
Tolerances, value limits, approval paths and exceptions – traceable and changeable later
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Audit trail per invoice
Which line was compared with what, who approved when, and what was handed over
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Training for accounting and buying
How deviations are worked through and what happens when an approver is away
Frequently asked questions about invoice intake
These solutions fit alongside
Purchase Request Automation
The step before: without a clean purchase order the match is missing its first column.
E-Invoicing Automation
Receive, validate and issue XRechnung and ZUGFeRD documents – obligation, not nice-to-have.
Approval Workflows
The same approval logic for everything else: purchases, contracts, exceptions.
Expenses and Travel Costs
Documents without an order: capture, check, approve and hand over to accounting.
Do you know where your most expensive invoice is right now?
In the free intro call we work through ten real invoices with the order and the delivery note beside them. Afterwards you know how many would have gone through without a query, and what tolerance that would take.
Book a free intro callWhere accounts payable automation creates value in everyday work
Supplier invoices are captured centrally, extracted, validated against rules, approved and handed completely to accounting or ERP.
Three concrete operating scenarios to compare with your own process.Unify invoice intake
Documents from inbox, portal and upload enter one shared intake route.
Prepare validation
Totals, supplier, purchase order and duplicates are checked before approval.
Complete accounting handoff
Original document, data, approval and validation status move to the target system together.
A strong fit when …
Documents, amounts and approvals follow explicit rules; exceptions must remain visible instead of being decided silently.
- You handle recurring supplier invoices using repeatable rules.
- The intake, target system and accountable business role can be named clearly.
- Exceptions are allowed to remain visible and move to people deliberately.
Deliberate automation boundary
Unclear coding, purchase-order discrepancies, suspected duplicates and tax exceptions stay with accounting.
Explore the technical approach and platformsEstimate time savings with your own volume
The calculator uses 11 minutes today and 3 minutes after automation as fixed example assumptions. It does not replace process analysis.
Illustrative estimate based on the visible assumptions — not a guarantee.