German Localization for the DACH Market: A Field Guide

German-speaking Europe is often the first non-English market a US or UK software company enters, and for good reason. Germany alone is the largest economy in the EU, and Austria and Switzerland add two high-income markets that can be served with largely the same language files. Buyers there are also unusually sensitive to quality. A B2B customer in Munich will read your privacy policy, check your Impressum and notice when the UI switches between formal and informal address halfway through onboarding.

This guide covers the decisions we see teams get wrong most often when localizing for DACH, from tone and layout to legal pages and the data protection questions that come up the moment you mention machine translation.

Du or Sie: decide before the first string

German has a formal (Sie) and an informal (du) form of you, and the choice runs through every sentence: verbs, possessives and imperatives all change. Switching later means retranslating almost everything, so make the call early.

There is no universal rule. Consumer apps, developer tools and younger brands increasingly use du, and many Berlin startups would sound stiff with anything else. Banking, insurance, healthcare, legal software and most enterprise B2B products still use Sie, and buyers in those sectors may read du as unprofessional. A reasonable test: how does your German sales team address prospects in email? Match that.

Whatever you pick, enforce it. Put it in the style guide, add it to the MT or LLM prompt, and add an automated check that flags informal pronouns (du, dich, dein) in a Sie product and vice versa. Also decide on capitalization (Sie is always capitalized; du is normally lowercase, though capitalized Du appears in some brand voices) and on gender-inclusive language. Forms such as Nutzer:innen are common in some sectors and avoided in others, so this is a brand decision rather than a translator's call.

Compound words and the 30% problem

German text typically runs around 30% longer than the English source, and individual UI strings can exceed that. The bigger issue is not average length but long single words. German builds compounds freely: account settings becomes Kontoeinstellungen, and password reset email becomes Passwort-Zurücksetzungs-E-Mail or a rephrased equivalent. A word with no break opportunities will overflow a button or table header that handled the English comfortably.

• Design for expansion: avoid fixed-width buttons, let navigation items wrap or truncate with a tooltip, and test table headers at the narrowest supported viewport.
• Enable hyphenation for German text with hyphens: auto and lang='de' on the element. Browsers ship German hyphenation dictionaries, and the result is far better than overflow.
• For known problem words in headings, insert soft hyphens (­) in the translation at sensible points.
• Give translators character limits per key. A limit forces a rewrite (Einstellungen instead of Kontoeinstellungen, where context allows) rather than an overflow discovered in production.
• Run pseudo-localization in CI that lengthens every string by 30 to 40% and adds umlauts, so layout bugs show up before translation starts.

Legal pages: Impressum and Datenschutz

German law requires most commercial websites and apps aimed at German users to publish an Impressum (legal notice) that is easy to find, typically linked from every page footer. Since May 2024 the requirement sits in the Digitale-Dienste-Gesetz (DDG), which replaced the older Telemediengesetz. It includes the company name, legal form, address, a fast means of electronic contact, the commercial register entry, the VAT ID where one exists, and the names of authorized representatives. Austria has comparable disclosure duties under its own laws, and Switzerland requires similar information on commercial sites.

The privacy notice (Datenschutzerklärung) is driven by GDPR, or DSGVO in German, and by the revised Swiss Federal Act on Data Protection for Swiss users. These pages should be written or reviewed by a lawyer familiar with the market. Do not machine-translate your US privacy policy and publish it. It will reference the wrong laws and miss required elements, and German competitors and consumer associations do send warning letters (Abmahnungen) over defective legal pages.

DE-DE, DE-AT and DE-CH are not the same

Most products can ship a single German locale and get away with it in Austria. Switzerland is different enough that a separate de-CH locale is often worth the small extra effort.

The ß rule alone justifies a de-CH variant for consumer products. Swiss users see Straße as a German import, much as British readers notice American spelling. The variant can be generated largely automatically from de-DE by replacing ß with ss and adjusting formats through Intl with the de-CH locale, followed by a short native review of marketing pages. Rounding also differs in practice: Swiss prices are typically shown to the nearest 5 Rappen.

Time is written in 24-hour format across the region (14:30 or 14.30 Uhr), weeks start on Monday, and calendar week numbers (KW 37) are widely used in business, so a date picker that shows week numbers will be appreciated by B2B users.

DSGVO-compliant machine translation

As soon as a German customer hears that their content will pass through machine translation, they will ask where it goes. If the strings are UI copy, the answer is easy, as there is usually no personal data involved. If you translate user-generated content, support tickets or documents, you are processing personal data and GDPR applies in full.

• Use a provider that offers a data processing agreement (Auftragsverarbeitungsvertrag) and does not use your content to train its models. Check the specific plan: free tiers of several services have different terms from paid API plans.
• Prefer EU data residency for processing and storage. DeepL, a German company, and the major cloud providers all offer EU processing options on paid plans. For LLM providers, check whether EU regional endpoints are available for the model you need.
• Strip or pseudonymize personal data before sending text for translation where you can. Names and email addresses rarely need translating.
• Document the setup in your record of processing activities and list the MT provider as a subprocessor. Enterprise buyers in DACH will ask for this list during procurement.
• For the most sensitive customers, a self-hosted open model running in an EU data center is a viable option, at the cost of more engineering and usually somewhat lower quality than the best commercial engines.

A workflow that holds up

The workflow we use for DACH launches looks like this. Strings live in the repository with keys, descriptions and character limits. A pipeline sends new and changed strings to the MT engine or LLM, along with the glossary and style guide (including the du or Sie decision). Automated checks validate placeholders, glossary terms, length and address form. A native German reviewer works through the flagged strings and all customer-facing flows in context, using screenshots or a staging environment. The de-CH variant is derived automatically and spot-checked. Legal pages come from counsel and bypass the pipeline entirely.

Budget roughly two to four weeks for the first pass on a mid-sized SaaS product, most of it spent on layout fixes, the termbase and review, not translation. After launch, continuous localization keeps new strings flowing within a day or two of being merged, which is what stops your German interface drifting back into English with every release.

Questions we get asked

Should my software use du or Sie in German?

Enterprise B2B, finance, healthcare and legal products generally use Sie. Consumer apps, developer tools and younger brands often use du. Match how your German sales and support teams already address customers, and apply it consistently.

Do I need a separate Swiss German locale?

Often yes for consumer-facing products. Swiss Standard German does not use ß, formats numbers with an apostrophe as the thousands separator and prices in CHF. A de-CH variant can largely be generated from de-DE with a short review.

Is machine translation DSGVO-compliant?

It can be. Use a paid plan with a data processing agreement, no training on your data, and EU processing where possible, and remove personal data before translation when it is not needed.