Accounts Payable: OCR, Approvals & ERP Posting

Inboxes, paper stacks, and double entry

Invoices arrived through many channels: PDF attachments, scans from the mailroom, and occasionally fax. Finance had to re-check amounts, vendors, and cost centres; mismatches with purchase orders caused back-and-forth. A standalone OCR tool without approvals and ERP connectivity would only solve part of the problem.

The shared-service team handled sales and purchasing queries in parallel—every manual double entry tied capacity needed for review and reporting. Status lived in email threads, not in a system with clear ownership.

Seasonal goods-receipt peaks doubled invoice volume; without queues and prioritisation, backlogs built although payment terms and cash discounts stayed unchanged.

Compliance and traceability

The client needed clear rules: who may approve up to which amount? which vendors are known? where must deviations from the PO be commented? Every step had to be audit-ready—without overwhelming staff with extra clicks.

Internal audit required traceability from extraction to posting proposal: OCR confidence, approver, resulting ERP transaction. GoBD-compliant storage of original documents was mandatory.

Different tax scenarios and reverse-charge cases must not be posted blindly—exceptions needed visible approval chains with rationale.

API-first between OCR, workflow, and ERP

The ERP offered REST for posting proposals; the bottleneck was upstream—intake, classification, matching, approval. An orchestrated pipeline was needed instead of isolated tools passing data via clipboard or Excel.

The wholesaler did not want a proprietary black box: workers, queues, and audit logs had to be maintainable and plug into existing monitoring. Python services and documented APIs fit better than pure desktop RPA for this document-heavy process.

Integration with purchasing and vendor master was central—invoices without PO reference or quantity variance had to surface early as tasks to purchasing or budget owners, not only at posting.

Pipeline from intake to posting proposal

We implemented an orchestrated chain: incoming documents are classified, text and key fields are extracted and matched to master data. Exceptions route as tasks to defined roles; in the standard case a short approval in a web UI is enough before a posting proposal is handed to the ERP.

The architecture connects process automation with API integration—document-driven but API-first to the ERP. Context also in the RPA vs API integration comparison and the integration topics hub.

“OCR alone was not enough—we needed approvals, PO matching, and ERP in one chain. Now we see status per document instead of searching mailboxes.”

Stable interfaces instead of manual hand-off

ERP connectivity uses documented REST calls and idempotent operations—so retries and batch runs behave safely. Workers process the queue with backoff on transient errors; critical events are written to an audit log for review and support.

Each posting proposal carries an external correlation ID; retries do not create duplicate postings. Failed ERP calls land in a dead-letter queue with IT alert—not silent data loss.

OCR results below confidence threshold go to manual capture with pre-filled fields—clerks correct deviations instead of retyping everything.

Engineering in Germany

Design and delivery were led by Groenewold IT Solutions in Leer/East Frisia: close collaboration with business and IT, a pragmatic MVP, then extensions for additional vendor and tax scenarios.

Training for approval roles and finance ran before go-live; shadow operation with parallel manual checks built trust in extraction and routing rules.

Budget planning is supported by the automation cost calculator; similar projects appear in automation references.

Monitoring, audit, and continuous optimisation

“Audit wants documents and decisions in one trail—that is why we log every step from OCR to ERP without passwords or raw PDFs in plain-text logs.”

Dashboards show cycle time, auto-match rate, and clarification reasons; monthly reviews with purchasing and finance refine matching rules and approval thresholds. Made in Germany—development and operational support from East Frisia.

Less manual capture, faster cycle times

Most invoices flow without duplicate work in finance; questions focus on true exceptions. Status and ownership replace “who last touched the email?” threads.

Cycle times from intake to posting proposal dropped measurably; cash discounts are missed less often. Purchasing gets structured tasks on PO variance instead of unstructured email chains.

The shared-service team gains capacity for analysis and vendor communication—not repeated typing of identical header data.

Reference for document-driven automation

The project shows how recurring document processes can be automated with OCR, workflows, and ERP connectors—while keeping business teams in control.

For wholesale and shared services the pattern transfers: API-first to ERP, human approval on exceptions, audit-ready log. More examples in the automation hub and integration topics.

Long term additional channels (EDI, supplier portal) can attach to the same pipeline—without rebuilding the core.