Your first e-invoice seems more complicated than it is. It contains the same information as any proper invoice. What's new is that the details have to be in fixed data fields so that your customer's accounting system can read them in automatically. This guide shows you the process in six steps, based on the rules in Germany.
If you don't yet know whether you need ZUGFeRD or XRechnung, first read ZUGFeRD or XRechnung: the difference and which format you need.
Step 1: Enter your own details properly, once
These details appear on every invoice. If you enter them correctly once, you avoid lots of mistakes later:
- Name or company name and full address
- Tax number or VAT identification number
- Bank details with IBAN
- Email address and phone number for questions
Transposed digits creep in easily, especially in the IBAN. A good program checks the check digits and warns you straight away.
Step 2: Add complete customer details
For an e-invoice, your customer needs complete master data: company name, street, postcode, town and country. If you supply goods or services to another EU country, their VAT ID is added. Some companies also give you a purchase order or reference number. Public authorities usually require a Leitweg-ID. Enter these details in the customer record, and they will appear on every invoice automatically.
Step 3: Enter line items, date of service and tax rate
Each line item needs a clear description, the quantity with unit (for example hours or pieces), the unit price and the tax rate. Then there's the date of service or service period. The date of service is one of the details most often forgotten.
Special cases need a note on the invoice, for example:
- Reverse charge for services to businesses in other EU countries: “reverse charge” (the recipient owes the tax)
- Kleinunternehmer (small business): a note on the tax exemption under Section 19 UStG
- Tax-exempt services: the reason for the exemption
All the details an invoice needs are listed in the checklist of required invoice details.
Step 4: Check before sending
With e-invoices there are two kinds of checks:
- Content: are all required details there, are the totals and tax correct?
- Technical: does the file comply with the EN 16931 standard? There are checking programs for this, called validators.
The technical check matters because your customer's accounting software may reject faulty files. Then you wait longer for your money.
Step 5: Create the format and send it
Create the invoice in the format your customer wants. For business customers that is usually a ZUGFeRD PDF; for public authorities, XRechnung. You can send both by normal email. You only need a special mailbox or portal if your customer requires it.
Important: send the file exactly as it comes out of the program. If you save a ZUGFeRD PDF again via “Print to PDF”, the embedded XML part is lost. Then it is no longer an e-invoice.
Step 6: Track payment and archive correctly
Note when the invoice was paid, and send a reminder in good time if the payment term has passed. E-invoices must be archived in their original format, including the XML part. Under current German law, invoices must be kept for eight years. A paper printout is not enough.
Common mistakes with your first e-invoice
- Date of service missing or only given as “as discussed”
- Invoice number used twice or not sequential
- Tax number or VAT ID missing
- Customer's reference number or Leitweg-ID missing
- ZUGFeRD PDF edited or re-saved afterwards
- Invoice changed after sending instead of being corrected with a credit note or cancellation invoice
Don’t want to do these steps by hand every time? In Invoice Studio you set up customers once and pick line items from your list of services. The app works out totals, tax rates, discounts and deposits. The e-invoice is created in one click as ZUGFeRD or XRechnung, and you create payment reminders or dunning letters as a PDF. Offline app, your data stays on your device, one-time purchase with no subscription.
Frequently asked questions
Can I create an e-invoice with Word or Excel?
No. Word and Excel only produce a normal PDF without structured data. For an e-invoice you need a program that can create ZUGFeRD or XRechnung.
Are there free options?
Yes. There are online forms you can use to create individual e-invoices. But you enter your customer data on someone else's servers and have to type a lot in again for every invoice. If you write invoices regularly, your own program saves you a lot of time.
How do I correct a wrong e-invoice?
An invoice that has been sent isn't simply changed. You create a cancellation invoice or credit note that refers to the original invoice, and then, if needed, a new, correct invoice.
Do I need internet to create e-invoices?
Not necessarily. Some programs run completely on your device. Then you only need internet to send the email.
How it works with Invoice Studio
Invoice Studio guides you through exactly these steps. You choose the customer, enter the line items, and the invoice check shows you live what is still missing, from the date of service to transposed digits in the IBAN. One click turns it into a ZUGFeRD PDF or an XRechnung according to EN 16931, checked with the Mustang validator. Invoice numbers run sequentially automatically, finished invoices are locked, and you make corrections properly with a credit note. The app runs offline in your browser with no subscription, and your data stays on your device.
This article is general guidance (as of October 2026) and is not tax advice. For your individual case, please talk to your tax advisor.