Invoice: Structure, components, and mandatory information required under German law

An invoice is far more than a simple proof of payment. It is a legally relevant document with tax and accounting implications. Whether you provide services, sell products, or work as a freelancer: your invoices must meet legal requirements and include certain mandatory details.

An invoice is a document with which a business bills a specific service or delivery and asserts its claim for payment against its customer. It serves as proof of a transaction for consideration and plays a central role in tax law, especially with regard to VAT.

The legal requirements for an invoice are set out in § 14 of the German VAT Act (UStG). Only if an invoice contains certain mandatory details does it entitle the recipient to input tax deduction, allowing them to reclaim the VAT paid from the tax office.

With a professional invoicing software you are automatically guided through all requirements. Mandatory details, number ranges, tax notes—everything is requested correctly and implemented in compliance with the law.

What is an invoice?

An invoice does not only document the claim for a payment. It also serves as evidence for the VAT that you owe to the tax office or can claim as input tax. For the tax office to recognize your invoices, you must provide certain information in accordance with § 14 UStG. If this information is missing, it can lead to problems with tax, payment delays, or even the repayment of input tax that has already been deducted.

Mandatory details on an invoice

According to § 14 UStG, the following mandatory details are required for invoices over 250 euros:

1. Stated VAT amount
2. Name and address of the issuing company
3. Name and address of the customer
4. Tax number or VAT identification number
5. Date the invoice is issued
6. Sequential, unique invoice number
7. Date of delivery or service
8. Description of the goods delivered or service provided
9. Net amount (remuneration)
10. VAT rate (e.g., 19% or 7%)

Additional mandatory details for e-invoices (EN 16931)

An e-invoice must be provided in a structured, machine-readable format (such as XRechnung or ZUGFeRD). To ensure it can be processed automatically by the recipient system, additional technical mandatory fields must be populated beyond the classic details:

• Leitweg-ID (for public authorities): For invoices to public contracting authorities (B2G), the Leitweg-ID is mandatory. It functions as a digital address and ensures that the invoice is correctly assigned within the authority’s structure.
• Buyer reference: Many companies in the B2B sector require a specific reference number (e.g., an internal project or cost center number) that must be stored in a designated data field.
• BT numbers (Business Terms): The European standard EN 16931 defines exact fields (so-called Business Terms) in which information such as the IBAN, the cash discount rate, or the email address of the contact person must be provided.
• BT codes for tax rates: Instead of free text, standardized codes must be used (e.g., “S” for the standard tax rate or “AE” for the reverse-charge procedure).
• Validity of the dataset: For tax purposes, an e-invoice is only considered proper if the XML dataset is technically error-free. A simple “typo” in the code can cause the invoice to be automatically rejected by the customer’s system.

Additional details – useful, but not mandatory

• Customer number or project number
• Payment term and bank details
• Cash discounts or discounts
• Order or contract number
• Phone number or email for queries

This information increases the traceability and professionalism of your invoice and may be requested by your customers. You can also predefine this in easybill and have it inserted automatically.

GoBD-compliant invoice creation and retention

The GoBD (principles for the proper keeping and retention of books) stipulate that invoices:

• must be stored in an unalterable manner
• must be documented completely and without gaps
• must be readable at all times, even after 8 years (statutory retention period)

With easybill, you create GoBD-compliant invoices automatically. All invoices are archived securely, exportable for your tax advisor, and can be found again at any time.

Invoice templates will no longer be valid in the future

Invoice templates in Word or Excel were helpful for a long time. But from 2025, new requirements will apply: With the mandatory e-invoicing requirement in the B2B sector, invoices must be able to be received in a structured format such as XRechnung or ZUGFeRD, and from 2028 the e-invoice will be mandatory for everyone. Classic templates will no longer be suitable by then at the latest; they meet neither the technical nor the legal requirements. Writing an invoice is much easier with an invoicing program. It saves a lot of time and grows with the number of invoices.

Invoice types at a glance

In practice, there are different types of invoices—depending on the business transaction:

Progress invoice

Partial payments for projects in multiple phases.
Example: a web developer bills project milestones separately.

Recurring invoice

Issued regularly for ongoing, unchanged services.
Example: monthly rent or a maintenance contract.

Recurring invoice (subscription)

For subscriptions or automatic billing cycles.
Easybill can generate these invoices automatically and on time.

Cancellation invoice / correction invoice

For correcting incorrect invoices. With just one click, Easybill creates a legally compliant cancellation invoice with the correct reference to the original number.

Small-amount invoice

For invoices up to 250 euros gross, reduced mandatory information applies. Easybill detects these cases automatically and adjusts the fields accordingly.

Credit note

Used when you grant your customer a credit or create credit notes for others yourself (e.g., for commissions).

Invoicing abroad: what you need to consider

If you issue invoices to other EU countries or to third countries, additional requirements apply:

• The customer’s VAT ID is required (for B2B within the EU)
• Note on the reverse-charge procedure:
  “Tax liability of the recipient of the service pursuant to § 13b UStG”
• Invoices in foreign currency or in English are possible
• Consideration of delivery thresholds (for B2C)

With easybill, you can also create multilingual invoices, state exchange rates correctly, and add automated reverse-charge notices.

Deadlines and retention of invoices

An invoice must be issued no later than six months after the service has been provided if the service is taxable and supplied to businesses (§ 14 para. 2 UStG).

According to §14b UStG business owners must retain invoices in compliance with the GoBD for eight years. The retention period was shortened in 2025 and begins at the end of the year in which the invoice is issued.

E-invoicing requirement from 2025

As of 1 January 2025, Germany will begin introducing the requirement for e-invoices in the B2B sector:

E-invoice means: structured, machine-readable formats such as XRechnung or ZUGFeRD; a PDF alone is no longer sufficient because it is not machine-readable. A valid e-invoice always also includes an XML file.

Easybill is prepared for both formats and already offers you the option to create, send, and archive e-invoices in compliance with the rules.

Professional invoice design – more than just a requirement

Invoices are also part of your brand presence. With easybill, you can:

• insert your logo
• choose custom colors and layouts
• create invoices in your own corporate design

This helps you make a professional impression on customers as well.