Your partner for digital invoice processes and e-invoicing since 2006 Mon–Fri 8:30 a.m.–5:00 p.m. (CET) bielefeld@optimal-systems.de
Invoice processing & e-invoicing for mid-sized and large companies

Digital invoice processing with enaio®: paper, PDF and XRechnung in one workflow.

Read invoices automatically, match them with purchase orders, approve them via workflow and pass them to SAP, DATEV or Microsoft Dynamics. Archived in an audit-proof way and ready for mandatory e-invoicing.

  • E-invoices, PDFs and paper in one single process
  • Self-learning recognition: 80% of data captured automatically at Reservix
  • Approvals via workflow and app, with discount deadlines in view
5.0 on Google 2,700+ customers of the OPTIMAL SYSTEMS Group Part of the KYOCERA Group
Free & without obligation

Your personal invoice processing live demo

Six quick clicks, then we show you your invoice process in the system.

Where does it hurt most?Question 1 of 6

Takes about 60 seconds No cost, no obligation

Companies and organizations that rely on enaio®

REWEADACPanasonicVoithGerman Football Association (DFB)De'LonghiKesseböhmerGerman Red Cross
The situation

Does this sound familiar from your accounting team?

Invoices arrive by post, as PDF and now as XML. Processing them by hand costs you twice: in working hours and in missed discounts.

An XRechnung, now what?

An XRechnung is pure XML code. Without suitable software, it can't be read, checked or archived properly.

Typing instead of checking

Invoice numbers, amounts, tax rates: data is entered into the ERP by hand, with every typo a risk.

Invoices get stuck

Approvals sit in inboxes or on desks, and nothing moves during vacations or sick leave.

Discounts lost

Long processing times cost early-payment discounts, and sometimes the reminder arrives before the approval.

Where is that invoice?

When suppliers or tax auditors ask, the search through binders and inboxes begins.

Paid twice

Without automatic matching, duplicates and deviations from the purchase order are often noticed too late.

Paper invoices take 22 minutes to process on average, digital ones just 5 to 7 minutes. (Study commissioned by the German Federal Ministry of the Interior, Goethe University Frankfurt)

Mandatory e-invoicing in Germany

From 2027, more and more of your invoices will arrive as XML

All companies in Germany have had to be able to receive e-invoices since 2025. From 2027, suppliers with prior-year revenue above €800,000 must also issue them, and from 2028 all suppliers. The share of XRechnung and ZUGFeRD invoices in your inbox will therefore grow quickly. They must be read, checked and archived in their original format in an audit-proof way. That's exactly what enaio® is made for.

Legal basis: German Growth Opportunities Act (Wachstumschancengesetz). Exceptions include small invoices up to €250. This overview does not replace tax advice.

  1. January 1, 2025All companies must be able to receive e-invoices
  2. January 1, 2027Obligation to issue e-invoices for revenue above €800,000
  3. January 1, 2028Obligation to issue e-invoices for all domestic B2B transactions
The solution

From incoming mail to posting, in one system

enaio® recognizes incoming invoices, whether paper, PDF or e-invoice, extracts the data and matches it with your master data and purchase orders. Workflows route every invoice to the right person, monitor deadlines and pass the checked data to your ERP or accounting system. Finally, everything is archived in an audit-proof way, including the approval log.

  • Digital invoice inbox with status at a glance
  • Supplier file with purchase orders and delivery notes right alongside
  • Open documents with one click, even from within SAP or Dynamics
Incoming invoice register in enaio® with workflow list and invoice preview

This is how an invoice moves through enaio®:

  1. Receive

    Post, email, XRechnung, ZUGFeRD, EDI or Peppol

  2. Extract

    OCR and self-learning recognition, including line items

  3. Check

    Matching with purchase order and master data, duplicates detected

  4. Approve

    Single or multi-level, with deputies and deadlines

  5. Post & archive

    Transfer to the ERP, GoBD-compliant in the original format

Before / after

What changes with digital invoice processing

Paper, PDF & email
With enaio®
Invoices are opened, stamped, copied and distributed by internal mail.
Every invoice lands digitally in the inbox and automatically with the person responsible.
Amounts and invoice numbers are typed into the ERP by hand.
The data is extracted automatically and passed to the ERP.
XRechnung files can't be read without a viewer and get printed out.
E-invoices are displayed legibly, checked and archived in their original format.
Approvals take days, even longer when someone is away.
Workflows with deputies and reminders, approval on the go via app.
Discount deadlines pass unnoticed.
Deadlines are monitored and overdue invoices escalated.
Tax audits mean searching through binders.
Invoice, account assignment and approval log are found in seconds.
Results from practice

What digital invoice processing delivers

Real figures from enaio® projects and independent studies.

80%of data recognized automatically

Invoices are captured electronically and processed via workflow, independent of location. Project duration around six months.

Reservix GmbH, ticketing
€70,000saved per year

The paper-heavy invoice process previously cost €105,000 a year. Introduced at four sites within six months.

Brückner-Werke KG, food industry
2 daysinstead of up to 2 weeks

Average processing time per invoice, with several thousand invoices per month and an SAP connection.

Mediengruppe Pressedruck, media
5–7 mininstead of 22 minutes

Processing time per invoice when handled digitally instead of on paper.

Study commissioned by the German Federal Ministry of the Interior, Goethe University Frankfurt
Features

Everything for fast, secure invoice processing

Standardized for a fast start, adaptable to your approval rules and systems.

Capture & recognize

All formats, one inbox

Paper, PDF, Word, email, XRechnung (UBL and CII), ZUGFeRD, Factur-X, FatturaPA or EDIFACT: everything ends up in the same process.

OCR & self-learning recognition

Supplier, invoice number, date, amounts, tax, discount and complete line-item tables are recognized. Recognition keeps learning during operation.

Verification

Anything not recognized with certainty, such as a missing VAT ID, goes to a verification dialog instead of slipping through unnoticed.

Check & approve

Invoice & plausibility checks

Automatic matching with supplier master data and purchase orders. Duplicates and deviations are flagged.

Approval workflows

Single, two-level or multi-level according to your rules: factual check, commercial check, payment approval. With queries and rejection.

Deadlines, deputies & app

Discount, reminder and blocking periods in view, deputy rules and follow-ups. Approve on the go with the enaio® app.

Post & integrate

ERP & accounting integration

Interfaces to SAP, Microsoft Dynamics 365, DATEV, Sage and many other systems. Checked data is transferred directly.

Open documents from the ERP

With image enabling, you open the matching document for every posting record directly from your ERP system.

Supplier file

Purchase orders, delivery notes, contracts and correspondence for each supplier sit right next to the invoice.

Archive & analyze

Audit-proof archive

Invoice, account assignment, posting stamp and approval log archived unalterably, e-invoices in their original format.

Status & analyses

Track the processing status of every invoice end to end, identify throughput times and bottlenecks.

For outgoing invoices too

Send invoices directly via Outlook and convert e-invoices when needed, for example into XRechnung format or FatturaPA for partners abroad.

See your invoice process in enaio®

In the free live demo, we show you how your invoices, whether paper, PDF or XRechnung, are captured, checked and approved automatically. No obligation and no preparation needed on your side.

Secure & compliant

GoBD-compliant archiving. Audit-ready documentation.

enaio® archives your invoices completely and unalterably, e-invoices in their original format, and logs every processing step. You are prepared for tax audits and meet the retention requirements for the entire statutory period.

GoBD E-invoicing (EN 16931) XRechnung & ZUGFeRD GDPR Audit-proof Cloud · On premises

Archived unalterably

Invoices and approval logs are stored in an audit-proof way and can be found at any time.

Original format preserved

For e-invoices, the XML file is the original. enaio® retains it and displays it legibly.

Complete log

Every step from receipt to payment is logged and stored as PDF alongside the invoice.

Roles & permissions

Everyone only sees the invoices they may process or approve.

Fast data access

Full-text search and filters for supplier queries and tax auditors' data access.

Your choice of operation

In your data center or in the cloud, in line with your IT and security requirements.

On request, we document your invoice process together in a procedural documentation.

References

What customers say about their digital invoice processing

Voices from accounting and finance.

„Automated invoice processing enables more flexible, location-independent processing – 80 percent of the data is recognized automatically, which saves a considerable amount of time.“Translated from German
Marcel ImschweilerOperational Team Lead, Finance and Accounting, Reservix GmbH
„Our previous costs for the paper-heavy incoming invoice process amounted to €105,000 a year. According to our savings projections, digitalization allows us to reduce these costs by €70,000.“Translated from German
Thuy Quynh NguyenFinancial accountant, Brückner-Werke KG
„We got off to a really good start with enaio® and have continuously developed the scope of services in parallel.“Around 220,000 documents per month are processed digitally at expert · Translated from German
Michael ReinhardtHead of Shareholder IT, expert SE
How it works

Three steps to digital invoice processing

  1. 1

    Free live demo

    You show us how your invoices are handled today, we show you the way in enaio®. With your own sample invoices if you like.

  2. 2

    Define process & interface

    Together we define approval rules, incoming channels and the connection to your ERP or accounting system.

  3. 3

    Go live & expand

    Projects such as those at Reservix or Brückner-Werke were completed in around six months. Afterwards, add contracts, personnel files and more on the same platform.

About us

Your partner for digital invoice processes in Bielefeld, Germany

OPTIMAL SYSTEMS Bielefeld has been digitizing document- and process-based workflows with enaio® since 2006, from incoming invoices and digital files to audit-proof archiving.

enaio® is developed by OPTIMAL SYSTEMS GmbH in Berlin. The group was founded in 1991 and has been part of the KYOCERA Document Solutions Group since 2020. You benefit from an established platform and personal support with short lines of communication.

Since 2006here for you in Bielefeld
2,700+customers of the OPTIMAL SYSTEMS Group
600,000+users work with enaio®
100+specialist solutions in enaio®
Patrick Zurawski
Your contact for digital invoice processingPatrick Zurawski
OPTIMAL SYSTEMS – A KYOCERA Group Company
Free checklist

Digital invoice processing & e-invoicing

What really applies to e-invoicing in Germany, what invoice processing software must be able to do and how much you save by going digital. Compact for accounting, controlling and management.

  • Mandatory e-invoicing 2025, 2027 and 2028 at a glance
  • Requirements checklist and 10 questions to ask providers
  • Savings calculator to fill in
  • Plus: product sheet for incoming invoice processing
FAQ

Answers to frequently asked questions

What is digital invoice processing?

In digital invoice processing, incoming invoices are captured electronically, read automatically, checked and approved via workflow, passed to accounting and archived in an audit-proof way. Paper invoices are scanned for this purpose; PDFs and e-invoices are processed directly.

How much does the live demo cost?

Nothing. The demo is free and without obligation. You see your invoice process in enaio®, ask your questions and get an honest assessment of effort and savings potential. If you like, you can then test it with your own invoices.

What's the difference between a PDF invoice and an e-invoice?

An e-invoice contains the invoice data in a structured, machine-readable format in line with the European standard EN 16931, such as XRechnung or ZUGFeRD. A simple PDF invoice or a scanned paper invoice does not legally count as an e-invoice.

Who has to receive and issue e-invoices in Germany, and when?

Since January 1, 2025, all companies in Germany must be able to receive e-invoices. From January 1, 2027, companies with prior-year revenue above €800,000 must issue their B2B invoices as e-invoices, and from January 1, 2028, all companies. Exceptions include small invoices up to €250. Your tax advisor can help with individual cases.

Isn't an email inbox enough for receiving them?

For receipt alone, an inbox is enough. But an XRechnung is an XML file: it has to be displayed legibly, checked, posted and retained in its original format. As the share of e-invoices grows, this quickly becomes time-consuming and error-prone without software.

Does enaio® also process paper and PDF invoices?

Yes. Paper invoices are scanned, in batches with enaio® capture or directly at the workstation. OCR and self-learning recognition extract the data from paper and PDF invoices, which are then processed in the same workflow as e-invoices.

Which ERP and accounting systems are supported?

enaio® works with leading ERP and accounting systems such as SAP, Microsoft Dynamics 365 (Business Central and F&O), DATEV and Sage. Other systems can be connected via standard interfaces and the REST API. Documents can also be opened directly from the ERP.

How long do invoices have to be retained in Germany?

Invoices are accounting vouchers. Since 2025, a retention period of eight years generally applies to them in Germany; previously it was ten. E-invoices must be retained in their original format. enaio® archives them in an audit-proof way for the entire period. Your tax advisor can confirm the period that applies to you.

Can we also switch over our outgoing invoices?

enaio® also supports outgoing invoices: invoices can be sent directly via Outlook, for example, and with enaio® classify-pro-SaaS-convert you convert e-invoices into other formats, such as XRechnung (UBL) or FatturaPA for partners abroad. We're happy to discuss the best solution for your outgoing invoices in the demo.

How quickly can we get started?

That depends on invoice volume, approval rules and interfaces. Projects such as those at Reservix or Brückner-Werke were completed in around six months; smaller scenarios are much faster. You'll get a realistic estimate in the demo.

Get started

Ready for invoice processing without typing and searching?

Experience enaio® in a personal live demo. Together we look at your invoices and systems and show how capture, checking, approval and archiving work together automatically.

  • Free and without obligation
  • Tailored to your ERP and approval rules
  • Personal contact in Bielefeld, Germany
Patrick Zurawski
Your contact for digital invoice processingPatrick Zurawski
Free & without obligation

Your personal invoice processing live demo

Six quick clicks, then we show you your invoice process in the system.

Where does it hurt most?Question 1 of 6

Takes about 60 seconds No cost, no obligation