Five Steps to E-Invoicing: The Practical Guide

Updated: 2026-08-02

“This is going to affect everyone” is no longer a forecast but a question of dates. This guide is for businesses still at the starting line that want to know what to do, concretely. Five steps, each with a checkpoint that tells you it is done.

Step 1: Review — how do invoices work today?

Before talking about software, write down how it works now. Answer four questions each for incoming and outgoing:

Incoming invoices

• Which addresses do they arrive at — and how many are there really?
• Who checks them, who approves them?
• How do they reach the bookkeeping?
• Where are they stored, and for how long?

Outgoing invoices

• What creates them — invoicing program, ERP, spreadsheet, word processor?
• How many go to businesses, how many to private customers? Only the B2B share is affected.
• Are there public-sector clients? Those already require an XRechnung.
• How are they sent and archived?

Checkpoint: You can write the path of an invoice, from arrival to storage, on half a page.

Step 2: The conversation with your tax adviser

This step deliberately comes before the software question — it determines what you are even shopping for. Four items belong on the agenda:

1. When does the sending obligation apply to us? Prior-year turnover decides: from 2027 above €800,000, from 2028 for everyone else. See E-Invoice Deadlines.
2. How will documents reach the bookkeeping? The structured record replaces the scan, so the handover route may change.
3. Who archives the original? The structured file must be retained for eight years, unalterably. See Archiving e-invoices.
4. Which formats do our customers expect? Tax advisers often know the sector practice.

What changes for the firm itself is covered in E-invoicing for tax firms.

Checkpoint: You know your cut-off date for the sending obligation and who retains the original.

Step 3: Assess software — update or switch?

Now for the technology. Ask your vendor in writing:

• Does the software produce e-invoices under EN 16931 — and in which format version?
• Does it read incoming XML and ZUGFeRD files, or only the ones it produced itself?
• Does it validate against the Schematron rules before sending?
• Is there a dedicated field for the Leitweg-ID?
• Does it archive the structured original?

If the answer is “no” several times over, a switch is due — plan it now, not in December before the deadline. At low invoice volumes a switch is often unnecessary; the trade-off is set out in E-invoicing software, the format decision in Which format?.

Checkpoint: You have a written statement from your vendor — or a decision in favour of a different tool.

Step 4: Clean up master data

The least glamorous step is the one most changeovers founder on. An e-invoice is checked by machine — what passed as a cosmetic flaw in the PDF world now causes rejection.

For every customer you need, in full:

• VAT ID or tax number — formally correct, not “it’ll be fine”
• complete address including country code
• payment terms and bank details in machine-readable form (IBAN, due date)
• Leitweg-ID for every public-sector client — a mandatory field in B2G
• Peppol ID if delivery runs over the Peppol network

The same applies to your own data: legal name, address, tax number and bank details must be stored exactly.

Checkpoint: A sample of ten customers has no empty mandatory fields.

Step 5: Training and a live test

Finally the reality check — with a real invoice, not a sample:

1. Create an actual invoice as an e-invoice.
2. Validate it against EN 16931 and the German business rules. Error messages are a good sign at this stage — they cost nothing now.
3. Send it to a cooperative customer and ask what arrived. Only their feedback proves the chain works.
4. Do the same for intake: open a received file, read it, store it.

Two sentences are enough for the team: the XML is the original — the printout is only a view. And: rejected invoices are data errors, not system failures; they get corrected and resent.

A realistic timeline

Start today

The cheapest way in is step 5 — brought forward. Take an invoice you wrote this week, generate it as XRechnung or ZUGFeRD and validate it. It takes a few minutes, costs nothing, and the resulting error list is the most honest process review you can get.