E-invoicing in OTM: supported formats and document types

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Electronic invoicing in OTM 9.5

Feature reference: OTM 9.5, dated 17 October 2026.

With OTM 9.5, all invoices and resource billing documents generated in OTM are electronic invoices using the updated standard. Output uses ZUGFeRD 2.5.2 / Factur-X 1.09.2, with the EN 16931 profile for regular B2B invoices.

Validation uses the official XSD files, Schematron rules and code lists for version 2.5.2.

Choose your output: PDF, XML or ZIP

Factur-X/ZUGFeRD combines a readable PDF with embedded XML invoice data. XRechnung is available as a standalone XML file. A third option creates a ZIP file containing both formats.

Choose the format to match the recipient’s requirements. An ordinary PDF without structured invoice data is not an equivalent electronic invoice.

Advance payments, corrections and cancellations

The extended document types provide a clear record of changes. Correcting an invoice, cancelling it in full and issuing a partial credit note are distinct actions:

New and extended document types
Document type	Identifier	Function
Advance payment invoice	XXXZ	A fixed amount or percentage. Advance payments received are credited against the final invoice.
Correction invoice	-B	A separate, traceable version referencing the original. Earlier versions remain available.
Cancellation invoice / cancellation or adjustment document	-S	A separate linked document cancelling an invoice or self-billed resource invoice; distinct from a partial credit note.

Document numbers and related versions

The numbers below are examples from the update information. They illustrate the identifiers for document types, corrections and cancellations; they do not represent a single chain of transactions.

Example document numbers
Document type / variant	Example number
Prepayment / payment request	XXXV26101039
Advance payment invoice	XXXZ26101367
Corrected advance payment invoice	XXXZ26101354-B1
Cancellation of an advance payment invoice	XXXZ26101354-S
Partial invoice	XXXT26101369
Corrected partial invoice	XXXT26101349-B2
Cancellation of a partial invoice	XXXT26101361-S
Final invoice	XXXA26101371
Corrected final invoice	XXXA26101370-B1
Cancellation of a final invoice	XXXA26101368-S
Customer credit note / partial credit note	XXXD261050
Agency-issued self-billed resource invoice	XXXN26001033
Cancellation of a self-billed resource invoice	XXXN26001027-S

Agency defaults and recipient-specific settings

Set default output formats for customer and resource documents under Administration → Settings → Accounts receivable and Administration → Settings → Accounts payable.

In PM → Customer administration, you can override the defaults for each customer and each alternative invoice recipient. New structured recipient fields include the electronic invoicing address and buyer reference.

Project documents and accounting at a glance

Originals, corrections and cancellation documents retain clear links to one another. Each version can be downloaded separately, with customer and resource documents shown in separate areas. The expanded views support day-to-day invoice processing:

Work areas and features
Area	New or enhanced
PM → Project documents	Originals, corrections and cancellation documents with clear references and a separate download for each version. Separate areas for customer and resource documents.
PM → Customer invoice	Corrections, cancellations and customer credit notes within the existing invoicing workflow.
Accounting → Invoices / Resource billing documents	Up-to-date document numbers and payment status. New document types in search and export, with access to document details for authorised users.
Accounting → Invoices / Resource billing documents → Document details	An overview of amounts, outstanding balances and related documents. Payment, early-payment discount, refund, cancellation and sending actions according to user permissions, plus a shared history.

Two billing workflows in the resource portal

OTM supports both agency self-billing and invoices issued by resources themselves. In both workflows, the output format follows the agency’s settings.

A self-billed resource invoice settles the resource’s services on their behalf. It is not the same as a customer credit note or a partial credit against a customer invoice.

Both resource billing workflows
Area	Available actions
Resource portal → Jobs → Self-billed invoices (agency self-billing)	View documents received from the agency, including details, status, related documents and downloads. Resources cannot post payments here.
Resource portal → Own invoices (resource-issued billing)	Preview, issue, send and cancel the resource’s own invoices. A shared detail view includes the document history.

Record follow-up transactions after project completion

Alongside corrections, cancellation documents and customer credit notes, you can record amounts actually refunded and correct payments entered in error. This provides a more complete record of transactions after a project has closed.

The distinction matters: a refund entry records money actually paid back; a reversal entry corrects an incorrectly recorded payment.

Refunds and reversal entries
Situation	Action in document details
Money actually paid back	Record refund
Correct a payment entered in error	Reversal entry

Tax scenarios and EU countries

OTM generates valid electronic invoice documents for all EU countries. Product information covers domestic transactions at standard or reduced tax rates, intra-EU transactions, reverse charge, tax-exempt exports to third countries and the German small-business scheme.

The appropriate tax treatment depends on the transaction and the data recorded. The format and submission channel must meet the recipient’s requirements. Generating a document does not itself mean submitting it to a national platform or a particular network.

Payment details and recipient references

IBAN, BIC and payment terms are included in the structured XML payment information. Keep bank details and payment terms up to date.

The electronic invoicing address and buyer reference form part of the structured recipient data. Buyer Reference helps the recipient allocate an invoice internally, for example to a purchase order, file reference or cost centre.

German public-sector customers may require a Leitweg-ID routing identifier. Confirm the identifier and submission channel with the recipient, including the details of any alternative invoice recipient.

Everyday billing checklist

Check names, addresses, invoice number and date, service description and date, tax identifiers, net amounts, tax and totals. Review the electronic invoicing address, buyer reference, payment details and selected output format.

Agree the format and submission channel with the recipient. When making changes, distinguish between a correction, a cancellation and a partial credit note. Use document details to review versions, payments and follow-up transactions together.

Retain the electronic original, including its structured data. A PDF visualisation or printout alone does not replace the data set. This article explains OTM features and does not replace case-specific tax or legal advice.