AI Invoice Automation That Posts Straight to Your ERP
Your AP team keys the same fields from every PDF, chases buyers about price variances and spots duplicates from memory. We build AI invoice automation that reads each invoice, matches it against the purchase order and goods receipt in your ERP, and sends only the exceptions to a person.
Read, matched against your ERP, routed when something is off, and posted with a record of every step.
Three-way match
Purchase order400 × €30.00PO-88213
Goods receipt400 receivedWarehouse, 14 Oct
Invoice400 × €31.20+4.0% over PO price
Price variance above your 2% tolerance. Sent to the buyer in Teams with the PO, the invoice and a suggested resolution.
09:14Fields extracted, confidence above threshold
09:14Bank details unchanged against vendor master
09:15Variance routed to buyer
11:02Buyer approved the new price
11:02Posted to ERP, audit record stored
Your ERP
SAP, Odoo or any system with an API
Exceptions only
People see the invoices the match cannot clear
Logged per invoice
Every field, match, approval and posting
Yours to run
Documented n8n workflows your team can extend
Ovidius clients include
What the Workflow Does With Every Invoice
Five jobs your AP team does by hand today, each handled by a step you can open and inspect.
CaptureEmail, portal, scan or e-invoice network Invoices arrive however your vendors send them: PDF attachments to an AP inbox, supplier portal uploads, scans, or structured e-invoices in formats such as Peppol BIS, XRechnung and FatturaPA. All of them land in one queue.
ExtractAny layout, with a confidence score per field A language model reads the header, line items, tax and bank details from layouts no template anticipated, and returns structured fields with a confidence score on each. Structured e-invoices skip this step. A field below your threshold sends the invoice to review instead of posting a guess.
MatchTwo-way and three-way, against live ERP data The workflow pulls the purchase order and goods receipt from your ERP and checks quantities and prices within the tolerances your controller sets. It also checks for duplicates and compares bank details against the vendor master, which is where invoice fraud usually shows up.
Route exceptionsTo the person who can resolve it Each exception is classified (price variance, missing receipt, possible duplicate, changed bank details) and sent to the right approver in Slack, Teams or email, with the invoice, the mismatch and a suggested resolution. One click approves or overrides.
Post and logThrough your ERP's API Cleared invoices post through the ERP's API. The workflow records every extracted field, match result, approval and posting, so an auditor can trace any invoice from inbox to ledger.
Exception queue
Sample · what reaches a person
ExceptionWhat the workflow foundRouted toSuggested resolution
Price varianceFoundUnit price 4.0% above the PO, outside a 2% toleranceRouted toBuyerSuggestedApprove and update the PO price, or reject to the vendor
No receiptFoundPO matches, but no goods receipt is booked yetRouted toWarehouseSuggestedHold and recheck when the receipt posts
Possible duplicateFoundSame vendor and amount as an invoice posted three days earlierRouted toAP clerkSuggestedReject as duplicate, with both invoices side by side
Bank detailsFoundIBAN on the invoice differs from the vendor masterRouted toFinance managerSuggestedVerify with the vendor by phone before any payment
Built on the ERP You Already Run
The workflow reads from and writes to your system of record, so the ERP stays the single source of truth for every invoice.
SAP S/4HANAPurchase orders, goods receipts and postings move through SAP's OData APIs. Our n8n and SAP Joule Studio guide walks through the unmatched-invoice triage workflow step by step.
OdooWe have built n8n layers on top of Odoo before, including the scheduling engine in our enterprise AI consulting case, which handles well over a thousand appointments a week.
Other ERPs and legacy systemsAny ERP with an API, and older systems through custom API wrappers. If you are not sure what yours can expose, an AI Audit maps it before anything is built.
Your rules and vendor knowledgeTolerances, payment terms and vendor-specific exceptions sit in a context layer the agents read before they decide, so a rule change is one edit.
E-Invoicing Mandates Are Changing What Reaches Your AP Inbox
Tax authorities across Europe and Asia are replacing PDF invoices with structured e-invoices sent through government platforms or the Peppol network. An AP workflow you build today has to handle both.
2019
Italy
B2B e-invoicing through the SdI exchange becomes mandatory.
Aug 2024
Malaysia
MyInvois rollout starts with the largest taxpayers.
Jan 2025
Germany
Every business must be able to receive e-invoices. Issuing phases in from 2027.
Jan 2026
Belgium
Domestic B2B e-invoicing over Peppol becomes mandatory.
Feb 2026
Poland
The KSeF national system becomes mandatory, largest taxpayers first.
Jul 2030
EU (ViDA)
E-invoicing and digital reporting for cross-border B2B sales within the EU.
In forceAdopted, not yet in force
Dates from each national tax authority and the EU VAT in the Digital Age package (2025). Confirm your own obligations with your tax advisor.
For your AP team, that means XRechnung, FatturaPA and Peppol BIS files arriving next to PDFs from vendors in countries with no mandate yet. We build intake to accept both. Structured invoices go through the same PO and receipt checks as PDFs, and the AI extraction step stays in place for documents that still need reading. Model use inside finance processes falls under the same controls we set up in enterprise AI governance engagements.
The Same Checker Pattern, Already in Production
The core of this page is an agent that checks every output against your rules before a person sees it. IES Limited runs that pattern today across four regulated insurance brands.
IES Limited · Insurance · 4 brands, 3 regions
A checker agent audits every draft against brand-specific rules before a human sees it
Agent
Draft produced
One of 11 agent-run stages
Checker agent
Audited against the rules
Banned terms, exact statistics, approved phrasing, as structured JSON
Human review
A person signs off
With the checker's findings in hand
Out
Published
Per brand, per region
In AP: extractionIn AP: PO and receipt matchIn AP: exception queueIn AP: ERP posting
80%
Less manual content production effort
4 → 1
Four brands run from one system
11
Agent-run stages from a single trigger
0
External agencies needed in 2026
Working with Owen and the Ovidius team has been a seamless experience; they are incredibly responsive and adapted quickly to our specific requirements.
How long does an AI invoice automation build take?
It depends on how many invoice sources, legal entities and ERPs are involved, so we scope it before you commit. A single intake-to-posting workflow on one ERP is usually a matter of weeks. A rollout across several entities and systems takes longer, and the scoping call tells you how much.
For reference, our GoKickflip build went from kickoff to production in 30 days. How we work sets out the four phases every build runs through.
Which ERPs and accounting systems do you integrate with?
SAP S/4HANA and Odoo are the systems we have built on most, and any ERP or accounting platform with an API is in scope. Older systems without a usable API can often be reached through custom wrappers. We confirm what your system exposes during scoping, before any build work starts.
What happens when the AI is not sure about a field?
Every extracted field carries a confidence score, and your controller sets the threshold. Below it, the invoice goes to review with the uncertain field highlighted, and nothing posts on a guess. Corrections are logged, and we use them to tune prompts and rules during the first weeks in production.
Can ChatGPT process our invoices?
ChatGPT can read a single invoice you paste into it. It cannot pull the purchase order from your ERP, apply your tolerances, send an exception to a buyer or post the result, and it keeps no audit trail your auditors can use. Those steps are the workflow we build, with a language model as one step inside it. Our AI solutions page covers the wider set of workflows built this way.
Where does our invoice data go?
The workflows run on n8n, which can be self-hosted inside your own cloud, and model calls go only to providers you approve. Hosting, retention and access rights are agreed in writing before the build starts, after an NDA and data governance agreement are signed. For policy across all your AI systems, see enterprise AI governance.
Do we have to change how our AP team works?
Your approval hierarchy, tolerances and posting rules stay as they are, because the workflow encodes them. What your team notices is that invoices that clear the match never reach their queue, and the ones that do arrive with the mismatch already explained.
Map Your AP Workflow on One Call
Bring a sample of last month's invoices and the name of your ERP. We will show you which ones a workflow would clear, which it would route to a person, and what the build would take. If invoices are one of several processes you want automated, our AI consulting team scopes them together.
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