How to Send a Certified Letter (내용증명) in Korea

A certified letter — called 내용증명 (naeyong-jeungmyeong) in Korean — is a postal service that officially proves what was sent, when, and by whom. While it does not carry binding legal force on its own, it serves as powerful evidence in disputes.

What Is a Certified Letter?

Based on Korea's Postal Act, the post office retains a copy of the letter's content for three years, certifying the sender, recipient, content, and date of dispatch.

Legal Significance

• Evidentiary power: Proves you sent specific content on a specific date
• Proof of notification: Demonstrates that legal notices (contract termination, demands) were delivered
• Statute management: Serves as evidence for interrupting prescription periods on claims

Certified Letter vs Regular Mail

Feature	Certified Letter	Regular Mail
Content retention	Post office retains for 3 years	Not retained
Proof of dispatch	Content + dispatch proof	Dispatch proof only
Legal evidence value	Strong	Weak
Cost	3,000–5,000 KRW	A few hundred KRW

How to Send a Certified Letter

1. Post Office Window

The traditional method:

What you need:

• 3 copies of the identical letter (1 for sender, 1 for recipient, 1 for post office)
• Names and addresses of sender and recipient
• ID card

Process:

1. Prepare three identical copies
2. Submit at the post office counter
3. Post office stamps all copies, keeps one, returns one to sender, mails one to recipient

Cost: Base fee 3,000 KRW + registered mail fee (total approximately 4,000–5,000 KRW)

2. Online via epost.go.kr

You can send certified letters online without visiting the post office.

Process:

1. Visit epost.go.kr and register/log in
2. Select the certified letter service
3. Enter sender and recipient information
4. Type or upload the letter content
5. Pay and send

Advantage: Available 24/7, no post office visit required

Essential Elements of a Certified Letter

1. Title: "Certified Letter" or "Notice"
2. Sender information: Name, address, contact
3. Recipient information: Name, address
4. Body: Clear and specific statement of the matter
5. Date: Date of writing
6. Signature or seal

Writing Principles

• State facts objectively — avoid emotional language
• Cite relevant legal provisions
• Clearly state your demands and deadlines
• Keep it concise — 1 to 2 pages

Common Use Cases

1. Contract Termination

Formally notify the other party of your intent to terminate a lease, service agreement, or other contract.

2. Payment Demand

Request repayment of a loan or payment of outstanding invoices, specifying the amount and deadline.

3. Lease Disputes

Demand return of security deposit, request repairs, or notify of contract violations.

4. Cease and Desist

Request cessation of defamation or copyright infringement.

Sharing Drafts with Your Lawyer

Since a certified letter can mark the beginning of legal proceedings, having a lawyer review the draft before sending is advisable. Sharing it via a regular messaging app like KakaoTalk or iMessage risks exposing sensitive legal content.

LOCK.PUB lets you share the draft in a password-protected memo, so only your lawyer can view it. You can set an expiration to auto-delete the content after review.

After Sending: Next Steps

1. Confirm delivery using the registered mail tracking number
2. Keep your copy safely stored (recommended: at least 5 years)
3. Track deadlines stated in the letter
4. Plan follow-up if no response — consider mediation or litigation

FAQ

Does the recipient have to comply?

A certified letter has no legal enforcement power by itself. However, ignoring it can work against the recipient in court.

Can only lawyers send certified letters?

No. Anyone can send one. A lawyer's review is recommended for legal effectiveness but not required.

How much does it cost?

Approximately 3,000–5,000 KRW via the post office. Lawyer fees for drafting are separate.

Takeaway

A certified letter is a cost-effective legal communication tool. When drafted properly, it can resolve disputes without litigation.

If you need a lawyer to review your draft, share it securely through LOCK.PUB — password-protected and with optional auto-expiration to keep sensitive legal documents safe.