A German invoice has to carry ten specific pieces of information under section 14 of the German VAT Act (Paragraf 14 UStG). Miss one and your client can lose their input VAT deduction, which is the fastest way to have an invoice sent back to you. This page lists every mandatory field, the exact wording for reverse charge and small business exemptions, and the simplified rules for invoices under 250 euros.
Under section 14 UStG an invoice must show: your full name and address, the client full name and address, your tax number or VAT identification number, the invoice date, a sequential invoice number, a description and quantity of what you supplied, the date of supply, the net amount broken down by VAT rate, the VAT rate and VAT amount, and any agreed discount arrangement.
If your turnover stays under the small business threshold you may invoice without VAT under section 19 UStG. You leave the VAT rate and VAT amount empty and add the sentence: Gemaess Paragraf 19 UStG wird keine Umsatzsteuer berechnet. If you show VAT anyway by mistake, you owe that VAT to the tax office.
For B2B supplies to a client with a valid VAT identification number in another EU country, you issue the invoice without VAT and state: Steuerschuldnerschaft des Leistungsempfaengers. Referencing Article 196 of Directive 2006/112/EC alongside it is common practice and helps the client accountant.
No. For a Kleinbetragsrechnung, an invoice of 250 euros gross or less, four items are enough: your name and address, the invoice date, a description and quantity of the supply, and the gross amount together with the applicable VAT rate. No invoice number and no client address are required.