SAP Invoice Processing

Outgoing and incoming invoices – completely in SAP,
without external platform, modification-free.

Output: check from the billing run, release, create in the required format, violate the rules
of EN 16931 – ZUGFeRD, XRechnung, Factur-X, Peppol BIS – with audit-proof filing
Input: all channels and formats – paper, PDF, e-invoice –, AI-supported receipts on request
recognise, assign, check, approve and post purchase order reference and goods receipt;
for non-critical transactions directly as a dark booking
One system: in an SAP-native add-on, without a cloud, no additional hardware or
Software necessary. The invoice data does not leave your SAP system.
Evidence: SAP Certified Integration, certification for SAP S/4HANA,
ISO 9001 certified development (DEKRA)

From January 1, 2027, the shipping obligation will apply to companies with more than €800,000 in sales in the previous year. Our recommendation: start pilot operation by mid-2026 at the latest. E-invoicing obligation 2027 in detail →

From 1 January 2027, outgoing invoices will become a mandatory task

Since January 1, 2025, every domestic company must be able to receive e-invoices. The transitional period for sending paper and PDF invoices ends on December 31, 2026: From January 1, 2027, companies with a total turnover of more than 800,000 euros in the previous year must also issue e-invoices in B2B traffic. From 1 January 2028, this will apply to all other domestic companies.

For SAP users, this means that the outgoing invoice must generate structured formats in accordance with EN 16931, archive them in an audit-proof manner, and keep the process traceable. Those who do not start this until December will test in productive operation. How MailCenter implements e-invoicing in SAP.

Exceptions apply, for example, to low-value invoices of up to €250, tickets and B2C sales. Small business owners must receive e-invoices, but not issue them. This overview does not replace tax advice.

since 01.01.2025
Obligation to receive for all domestic B2B companies
until 31.12.2026
Transitional period: paper and PDF still permissible when sending
from 01.01.2027
Obligation to exhibit from 800,000 € previous year’s turnover
from 01.01.2028
Obligation to issue for all other companies

Your contact person

Michael Struck

Schedule a demo

The overall process

One process, two directions – both in SAP

In many projects, outgoing and incoming invoices are considered separately and solved with separate tools. Technically, however, they share the same building blocks: formats, validation, release logic, archiving. MailCenter is based on this common basis – that’s why you see both directions in the same cockpit and with the same authorization logic.

SAP S/4HANA · SAP ECC

Outgoing invoice

from receipt to recipient

1. SAP Document
Billing Document from SD / FI
2. Invoice control
Lock, check, release
3. Create format
XRechnung, ZUGFeRD
4. Shipping
E-Mail, Peppol, Portal
5. Archive
Audit-proof

Receipt of invoices

from receipt to posting

1. Entrance
Email, Peppol, Portal, Paper
2. Detection
Readout & Validation
3. Testing & Assignment
Ordering, Goods Receipt
4. Release
Workflow in the department
5. Booking & Archive
incl. Duplicate check

Both paths run within your SAP system: the same master data, the same roles, one archive. No intermediate memory, no second database.

Outgoing invoice

Tested and not just out quickly

An incorrect invoice from the customer costs twice: credit note, recreation, queries – and trust. Therefore, before sending, there is a control level that your specialist department operates itself, without SAP authorization, in the customer master.

E-invoicing with SAP

Create, validate, and send XRechnung and ZUGFeRD directly from SAP S/4HANA and SAP ECC – in the standard process, not as a special route.

E-invoicing in SAP →

Invoice voucher

Check, block or release outgoing invoices as PDF on the screen. The receipt remains blocked until an employee has released it.

Check invoices before sending →

Formats & Validation

EN 16931, XRechnung, ZUGFeRD, Factur-X: MailCenter checks outgoing invoices against the target format before they leave the company.

Formats & Validation →

Peppol

Exchange invoices via the Peppol network – the shipping route that international customers increasingly require.

Peppol with SAP →

Receipt of invoices

Recognize, assign, check, book

Incoming invoices arrive in all ways: as e-invoices, as PDFs in the mailbox, as paper by post. In the invoice receipt cockpit, you bundle all documents in one place, assign them to purchase orders, cost centers, and goods receipts, and manage the release where it belongs – in the business department, not in the circulation folder process. In the case of non-critical processes, the dark posting is done directly, without a human having to touch the receipt.

Processing of incoming invoices

Central overview of all incoming invoices, AI-supported recognition and assignment, dark posting for non-critical transactions, duplicate check and audit-proof filing.

The invoice receipt cockpit →

Invoice Verification & Rejection

Rule-based verification against purchase order and goods receipt. Anything that does not fit is automatically returned to the supplier by e-mail with justification.

Invoice approval

Approval workflows with substitution rules and value limits, completely in SAP – paper-based approval procedures are no longer necessary.

Sharing in SAP →

Adjacent Documents

Adjacent Documents in the Procurement Process

The invoice is rarely the first document in the process. If you also process order confirmations and goods receipts digitally, you already have clean reference data for invoice verification – and significantly fewer clarification cases.

Order Confirmation & Advice

Automatically compare incoming order confirmations and ASNs, detect deviations at an early stage.

Order confirmation in SAP →

Goods receipt

Record goods receipts digitally and make them available as a reference for invoice verification.

Goods receipt in SAP →

Recommended by SAP customers

More than 200 companies rely on our solutions. These include customers such as Dr. Oetker, Augustiner Bräu, Carl Zeiss, Siemens Healthineers, Sortimo, thyssenkrupp and many more …

“The fact that we can combine invoices and attachments within one e-mail is a major advantage of the solution for us.”

Duisburger Versorgungs- und Verkehrsgesellschaft mbHWolfgang Scheffler | SAP Senior Consultant (Project Management)

“Thanks to the dialog options, the MailCenter simultaneously ensures optimized accounts receivable management and clean, always up-to-date master data in our accounting.”

Pneuhage Management GmbH & Co. KGLuigi Borella, Application Support WWS Team/ Corporate Controlling

“We are also fulfilling a wish of many customers who want a format that can be processed automatically. They want to read the data directly into their systems. This is only possible to a limited extent with normal PDF files, as the data always has to be typed manually from there.”

Hekatron Fire ProtectionMarco Müller, IT Project Manager | Hekatron Fire Protection

Companies trust MailCenter

Formats & Shipping Routes

What formats and channels MailCenter covers

E-invoicing is not a single format, but a European standard with national characteristics. Crucially, your SAP system is capable of both the format the recipient expects and the way they expect it.

Format / Path	What it is	Typical use
XBill	German XML profile of EN 16931	Public Contracting Clients, B2B Germany
ZUGFeRD / Factur-X	Hybrid: PDF with embedded XML	B2B, when people also check the recipient
Peppol BIS 3.0	Format plus international transport network	Cross-border, group requirements
E-mail / Portal / Paper	Classic channels in the entrance	As long as your suppliers use them

In the inbox, MailCenter processes all the above paths in parallel. You don’t have to force your suppliers onto one channel to work digitally internally.

Frequently asked questions about invoice processing in SAP

What does invoice processing in SAP involve?

Invoice processing includes both directions: outgoing invoices with creation, control, formatting and dispatch as well as incoming invoices with capture, recognition, checking, release, posting and archiving. Purchase order confirmations and goods receipts are also added because they provide the reference data for invoice verification.

When is e-invoicing mandatory for our company?

Domestic B2B companies have had to receive e-invoices since January 1, 2025. Companies with more than 800,000 euros in sales in the previous year must exhibit from January 1, 2027, and all others from January 1, 2028. Deadlines, exceptions and permissible formats in detail can be found in our overview of the e-invoicing obligation 2027.

Do we need an external platform for e-invoicing?

No. MailCenter is an SAP add-on and runs in your system. Formats are created and validated in SAP, and they are sent from SAP. An additional portal with its own database and its own operational responsibility is not required.

Does this also work with SAP ECC 6.0?

Yes. MailCenter supports SAP ECC 6.0 and later, as well as SAP S/4HANA, including RISE with SAP S/4HANA Cloud in certified integration.

Which formats do we need to support?

The European standard EN 16931 is decisive. In Germany, XRechnung and ZUGFeRD are the most common variants from version 2.x, and Peppol BIS 3.0 is being added internationally. Which format is specifically required depends on the recipient – MailCenter covers the aforementioned in parallel.

What happens to paper and PDF invoices that continue to come in?

They are processed in the same cockpit. Paper and PDF receipts are captured, recognized and transferred to the same review and approval process as structured e-invoices. So you don’t have to change your suppliers by a deadline.