In law, tiny details aren’t “tiny.” A comma, a defined term, or one slightly-off phrase can decide whether a contract holds up, a merger goes through, or an immigration file gets approved. Once a document has to work in another language, that pressure only increases. Legal translation isn’t just translating words, it’s making sure the document still works inside a different legal world.

And because the consequences are real, a translation mistake can trigger expensive setbacks: failed filings, drawn-out disputes, unexpected liability, or even an agreement that ends up unenforceable.

In this post, we’ll walk through the mistakes that show up most often in legal document translation—and what to do instead so you’re not the one paying for them later.

1. Choosing Literal Words Over Legal Meaning

A classic beginner's error is going “word for word.” In everyday writing, that can be good enough. In legal writing, it often breaks the meaning. Legal terms are tied to specific definitions and procedures, and the closest dictionary match in another language may point to the wrong concept entirely.

Example: Think about the phrase “Prayer for Relief.” A normal dictionary definition of “prayer” is religious. If someone translates it that way, it can sound like the plaintiff is making a spiritual request. In court filings, though, it’s simply the section that lists what the filer wants the judge to order (damages, an injunction, fees, and so on). Translate it literally, and the other side may not even be clear on what relief is being requested.

2. Ignoring Differences Between Legal Systems

Legal ideas don’t travel perfectly across borders. Terms and roles come from particular systems—Common Law, Civil Law, and local procedures inside each country. A frequent mistake is assuming that a concept in one jurisdiction operates the same way elsewhere. If the translator doesn’t understand the target legal framework, they can choose a term that either doesn’t exist or carries the wrong authority.

Example: “Notary Public” is a good one. In some English-speaking countries, a notary mainly verifies identities and witnesses signatures. In many European systems, a notaire/notario is a senior legal professional with much broader powers. If you translate a document for a European authority using the equivalent of “signature witness,” you may end up with paperwork that gets rejected because it’s missing the involvement of the official role the local system expects.

3. Treating Nuance as Optional

Legal writing can feel heavy and repetitive, but it’s built that way to avoid loopholes. One misplaced modifier or swapped connector can shift responsibility, timelines, or rights. Translators who aren’t used to legal drafting sometimes try to “smooth it out” to make it read nicer. The problem is that readability edits can quietly remove protections the original text was relying on.

Example: In contracts, “may” and “shall” are not interchangeable. “May” usually signals permission or discretion; “shall” is typically used to impose a duty. If a translator replaces one with the other because it “sounds cleaner,” a clause that was meant to be optional can become mandatory—or the reverse. That’s not style. That's the substance.

4. Forgetting the "Small" Details: Seals, Stamps, and Headers

A legal document isn’t only its paragraphs. Courts and agencies often care about everything around the text too: headers, registration numbers, handwritten notes, marginal annotations, seals, and stamps. A common misstep is translating only the main body while skipping those extras. For official use, that can make the translation look incomplete—or suspicious.

Example: Say you’re submitting a birth certificate for an immigration application. The certificate has a faint stamp on the back from a local registry office. If the translation ignores it because it looks minor or hard to read, an officer may refuse the document because they can’t confirm the issuing authority or the record’s authenticity.

5. Relying on the "Bilingual Friend" or Generalists

To cut costs, some companies hand legal translation to a bilingual employee or a general translator who mainly works on non-legal content. Speaking both languages fluently helps, but it doesn’t replace legal training. Legal translation sits in a narrow lane: you need language skill and enough legal knowledge to recognize what a clause is doing.

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Example: Someone who does a great job translating product descriptions might not be familiar with the specialized phrasing inside a pharmaceutical patent. If a technical definition is slightly off—or a key limitation is translated too broadly—you could weaken your protection and create room for challenges. In the worst case, you learn the hard way when a competitor argues your translated text doesn’t say what you thought it said.

6. The Over-Reliance on Artificial Intelligence

Free online translation tools make it tempting to drop in a contract and hit “translate.” AI can be useful, but legal translation is a context-heavy task, and AI often defaults to the most common meaning of a word—not the legal one.

There’s also a serious privacy issue: uploading sensitive documents to free tools can expose confidential information, especially if you don’t know how the data is stored, processed, or retained.

Example: Names can break things in surprisingly messy ways. If someone’s last name is “Hunter,” an AI system may translate it as the common noun for a person who hunts. Suddenly the translated contract refers to a different “person” than the original. That kind of error isn’t just embarrassing—it can undermine identification and make the document unusable.

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7. Skipping the Quality Control Phase

Even careful professional legal translation services can miss something. In long documents, small mistakes hide easily: a typo in a date, a missed “not,” a number copied incorrectly, a defined term used inconsistently. A major mistake is treating the first completed translation as final. Solid legal translation workflows include a second set of eyes—often called the “four-eye principle”—so another qualified reviewer checks terminology, figures, and legal consistency.

Example: Imagine a financial agreement that references a payment of $1,000,000. If one zero disappears and nobody catches it, the translated version might show $100,000. That one character can create a $900,000 gap, and by the time someone notices, signatures may already be on the page.

8. Neglecting Data Safety and Privacy

Legal documents usually contain information you don’t want floating around: addresses, account numbers, personal IDs, trade secrets, or deal terms. A frequent mistake is sending files through unencrypted email, sharing them over insecure links, or hiring providers without clear confidentiality rules. A leak during translation can be just as damaging as a mistranslation.

Example: Suppose you’re translating documents for a confidential merger, and the translator forwards the files through a personal email account with weak security. If that account gets compromised, the leaked information can trigger market rumors, insider trading concerns, or a deal that collapses before it’s announced.

How to Protect Your Legal Documents from Wrong Translation?

The price of getting legal translation wrong is usually far higher than paying for a careful process upfront. If you want your documents to stay accurate and enforceable, these steps help:

• Hire certified experts: Choose translators with specific training or credentials in legal translation, not just general fluency.
• Request a review: Ask for a multi-step workflow that includes translation plus editing and proofreading by someone qualified.
• Use terminology lists: Share a preferred glossary so key terms stay consistent across contracts, filings, and related documents.
• Demand security: Work only with providers who offer secure file transfer and are willing to sign non-disclosure agreements.
• Don't wait until the last minute: Rushed timelines increase the odds of human mistakes, especially on long or technical documents.

Do you have documents that require professional translation? At Transpose, we provide accurate, certified translations that meet ISO 17100 and 18587 standards for legal, official, or regulatory use. For consultation or quote, email us at trp@transpose.ch or call +41 22 839 79 79 today.