When a foreign agency asks for a "certified translation" of your Korean document, the requirement sounds simple — until you try to find out what "certified" actually means. The word maps to four different things depending on the country, and picking the wrong one wastes weeks of processing. This guide defines each option, walks through four common scenarios, compares cost and timeline, and ends with a decision flowchart you can apply to any document.

The four terms — defined

Certified translation — translation accompanied by a signed statement from the translator (or translation company) attesting that the translation is accurate and complete. No notary or government involvement. Used widely in US, UK, Canada, Australia.
Notarized translation — translation where a notary public has witnessed the translator signing the attestation. The notary does not vouch for translation accuracy — only that the translator's signature is genuine. Used in Vietnam, much of Asia, some EU countries.
Sworn translation (traduction assermentée / beeidigte Übersetzung) — translation done by a translator officially appointed by a court. The translator has a unique seal and is legally responsible for accuracy. Used in France, Germany, Spain, Brazil, Argentina, and most civil-law jurisdictions.
Apostilled translation — sworn or notarized translation that has been apostilled by the foreign ministry. Adds international recognition. See apostille-for-korean-documents.

These are not interchangeable. A US-issued certified translation will be rejected by a German court that wants a sworn translation. A Korean notarized translation may not be accepted by a French consulate without further apostille.

Four scenarios — and the right choice

Scenario 1: Korean academic transcript for a US graduate school US universities accept certified translation from a "professional translator or translation service". No notary needed; no apostille. Submit the translation alongside the original transcript. Pick: certified translation.

Scenario 2: Korean marriage certificate for F-6 spousal visa in Vietnam Vietnamese embassy and family-affairs office want notarized translation. Apostille on the Korean original (post-2023) makes the process smoother. Pick: notarized translation + apostille on original.

Scenario 3: Korean court judgment for enforcement in Germany German courts require sworn translation by a court-appointed German translator. Korean-side notarization does not satisfy this — must be done by a sworn translator in Germany. Pick: sworn translation in destination country.

Scenario 4: Korean business registration for a UAE business license UAE government accepts certified translation but requires apostille on the Korean original plus consular legalization at the UAE embassy. Pick: certified translation + apostille + consular legalization.

Cost comparison

Option	Korean-side cost	Timeline	International recognition
Certified translation	KRW 30–80K / page (translator)	1–3 days	Limited to common-law countries
Notarized translation	Above + KRW 30K notary fee	1–2 days notary	Most Asia, EU on case-by-case
Sworn translation (in destination)	Varies, often EUR 50–150 / page	1–2 weeks	Strong in civil-law countries
Apostilled certified or notarized	Above + KRW 1,000 MOFA fee	Plus 1–3 days	Strong (Hague Convention)
Consular legalization	Above + embassy fee	Plus 5–15 business days	Required for non-Hague countries

Which embassies accept what

A snapshot of major destinations (verify with the specific consulate before submitting):

US (visa, university, employer) — certified translation. Apostille on original if for legal/court use.
UK (visa, education) — certified translation by a member of the Institute of Translation and Interpreting or equivalent.
Canada — certified translation; sworn translation accepted; affidavit-of-translation common.
Australia (NAATI requirement) — translation by a NAATI-accredited translator (preferred but not always mandatory).
Germany / Austria — sworn (beeidigte) translation by a German/Austrian court-appointed translator.
France — traduction assermentée by a translator on the court list. Korean-side notarization not accepted alone.
Spain / Italy — sworn translation by a national translator; apostille on Korean original.
Vietnam — notarized translation done in Vietnam OR Korea-side notarization + apostille (post-2023 Hague accession).
Japan — certified translation in many cases; some procedures want translation done in Japan with hanko-equivalent verification.
China — must be translated by a Chinese-licensed agency in China; Korean-side translation usually re-translated.

Decision flowchart

Is the destination a common-law country (US, UK, Canada, Australia)? Yes → certified translation.
Is the destination a civil-law country in Europe (Germany, France, Spain, Italy)? Yes → sworn translation by a court-appointed translator in the destination.
Is the destination in Asia or Latin America?
- For Vietnam, Japan, Korea-bound documents going to Korea: notarized translation acceptable.
- For China: translation by a Chinese-licensed agency required.
Is the destination Hague Convention member? Yes → apostille on the Korean original is sufficient legalization. No → apostille + consular legalization at the destination's embassy in Seoul.
Is the document being used in court or for government registration? Yes → notarized at minimum; sworn translation if available in destination. No → certified usually fine.

How ZenTrans fits in

ZenTrans produces the translation. The certification/notarization/apostille step is handled by:

Certified translation: a ZenTrans-supported certified translator signs the AI-produced output. We provide a certification statement template.
Notarized translation: take the ZenTrans output to a Korean notary public (공증사무소) — they witness a translator's signature on the certification statement.
Sworn translation: ZenTrans is not currently sworn-translator-certified. For destinations requiring sworn translation (Germany, France, Spain), use a destination-country sworn translator who may use ZenTrans output as a first draft.
Apostilled translation: combine notarized translation with apostille on the Korean original. See apostille-for-korean-documents.

Frequently asked questions

Can I be my own certified translator? For most US/UK/Australian uses: no — must be a "neutral third party". For some informal uses: yes, with a signed declaration. Always ask.

The translator and notary are the same person — is that OK? No. The notary witnesses the translator's signature; if they are the same person, the notarization has no independent value. Different signatures required.

My document was translated by AI. Can it still be certified? Yes. AI-produced translations (like ZenTrans output) can be reviewed and certified by a human translator who attests to accuracy after their review. The AI is the tool, the human is the certifier.

Do I need to recertify if I want to use the translation in a different country? Often yes. A translation certified for the US may need additional notarization or apostille for use in Germany.

Picking the right certification once saves you weeks of rework. When in doubt, ask the receiving party in writing for the exact term they require — "certified", "notarized", "sworn", or "apostilled" — and match it precisely.

Ready to translate a document and pair it with the right certification? Open ZenTrans and upload your first document — the first 5 pages are free.