You got the part-time job at the convenience store, or an offer from a company in Korea, and then the message arrives on KakaoTalk: "Please send a photo of your ID card." If you are a foreign resident, that usually means your Residence Card (외국인등록증, formerly called the Alien Registration Card or ARC), or your passport if you have not received the card yet.
Before you snap a photo, a few questions are worth asking. Does the employer really need the full registration number right now? Why would they want your address or the issue date? And what stops that image, sitting in a manager's phone or an HR inbox, from being reused somewhere else?
The honest answer is that it depends on the stage of hiring and the purpose. This guide walks through the Korean rules that limit who may collect registration numbers, splits the process into "applying" and "hired", shows which fields you can hide at each stage, and explains how to stamp a semi-transparent "for submission to X only" watermark across the copy so it is hard to reuse.
1. Korean law only allows registration numbers to be collected with a legal basis
The core rule is Article 24-2 of the Personal Information Protection Act (개인정보 보호법), titled "Restrictions on Processing Resident Registration Numbers." In principle, an organization may not process a resident registration number at all. The exceptions are narrow:
- a statute or presidential decree specifically requires or permits processing the number,
- it is clearly necessary to protect someone's life, body or property in an emergency, or
- the Personal Information Protection Commission designates a comparable unavoidable case by public notice.
The same article requires numbers that are processed to be stored with encryption. In plain terms, "we want to confirm who you are" is not by itself a reason to collect your full number. An employer gets that reason when it has to file legally required reports about you.
For hiring, the Fair Hiring Procedure Act (채용절차의 공정화에 관한 법률) also applies to workplaces with 30 or more regular employees. Its Article 4-3 bans asking applicants for information unrelated to the job, such as place of origin, marital status, assets, physical traits, or family members' education and jobs. Registration numbers are not named there, but it supports the view that an address on an ID copy has no place in the application stage.
2. Applying and being hired call for different information
An employer genuinely needs your number once you are hired and paid. Enrolling you in the four social insurances (국민연금 national pension, 건강보험 health insurance, 고용보험 employment insurance, 산재보험 industrial accident insurance), withholding income tax and filing payment statements all require it, and the relevant laws allow it. Even day-labor shifts need it for the employment insurance work report and the daily-wage income statement.
During the application or interview stage none of those filings exist yet. If an ID copy is requested then, the purpose is usually identity or age checks, so your name, date of birth and photo are enough.
| Situation | What the employer actually needs | Last 7 digits | Recommended approach |
|---|---|---|---|
| Applying / before interview | Identity, age | Hide | Show date of birth only, add watermark |
| Right after hiring | Insurance enrollment, tax withholding | Needed | Write the number on HR forms instead of sending an image |
| Day labor / short shifts | Work report, daily income filing | Needed | Write it on the contract; watermark any copy |
| Age check only | Confirm age | Hide | Show first 6 digits and photo |
| Petition or affidavit attachment | Confirm the signer | Usually hidden | Follow the recipient's instructions |
Even after hiring, a photo is not the only option. Writing your number directly on the employment contract or HR record card gives the employer what it needs without creating an image file that can be forwarded. If HR insists on a copy, protect it with the methods in sections 3 and 5.
3. What to hide and what to keep, field by field
Korean ID cards carry more than one sensitive field. The easiest one to overlook is the issue date. Korea's government portal Gov24 (정부24) offers an ID authenticity check that takes a name, registration number and issue date and tells you whether the card is valid. A copy showing all three makes it much easier for someone to pass as the genuine cardholder.
| Field | Applying / interview | After hiring | Why it matters |
|---|---|---|---|
| Name | Show | Show | Basic identity |
| First 6 digits (date of birth) | Show | Show | Age check |
| Last 7 digits | Hide | Needed for filings | Core data for identity theft |
| Address | Hide | Only if asked | No basis at application stage |
| Issue date | Hide | Hide unless asked | Used in authenticity checks |
| Photo | Show | Show | Face match; hiding it defeats the copy |
| Driver's license serial code | Hide | Hide | Used in license verification |
| Back of the card | Do not send | Do not send | Rarely needed for work |
4. What changes if you are a foreign resident
Most of the rules above apply to you exactly as they do to Korean citizens, but a few points are different.
- Your Residence Card stands in for the Korean ID card. Under Article 88-2 of the Immigration Act (출입국관리법), alien registration and reporting a change of residence replace the resident registration that Koreans do, and the Residence Card replaces the resident registration card. That is why employers ask for it, and your foreign registration number (외국인등록번호) plays the same role as a citizen's resident registration number.
- Health insurance is the clearest reason HR needs your number. A foreigner who has completed alien registration and works at a covered workplace is enrolled as an employee subscriber, at the same rate as Korean workers (National Health Insurance Act, Article 109).
- Pension and employment insurance depend on your visa and nationality. Foreign employees are generally covered by the national pension unless their home country does not cover Koreans (reciprocity). Employment insurance applies to E-9 and H-2 workers, while for other visas it is mandatory for some (for example F-5) and opt-in for others (for example F-4 and E-7). Either way, the employer needs your number to file.
- No Residence Card yet? New arrivals sometimes send a passport copy. The two lines of characters at the bottom (the machine-readable zone) repeat your passport number and date of birth, so treat them like the last digits of a registration number and cover them unless the employer specifically needs them.
Rules vary by visa status, nationality and social security agreements. Confirm your own case with the National Pension Service (1355), National Health Insurance Service (1577-1000), the Employment Center (1350), the National Tax Service (126) or the Immigration Contact Center (1345). If you hold a student or other restricted visa, check separately that you are allowed to take the job before you hand over any documents.
5. How to hide fields so they cannot be recovered
A careless redaction can look hidden while the data is still there.
- Cover the card before you shoot. A sticky note over the last digits and the issue date is the most reliable method, because the original file never contains the data.
- If you edit, use a solid, opaque color. Use the pen tool at 100% opacity in black and go over it several times. Semi-transparent highlighters, light mosaics and blur can often be undone by adjusting brightness.
- Check that you are sending the edited file. Some phone galleries keep the original and store edits separately. Reopen the edited image to confirm, then attach that file.
- PDF annotation boxes can be deleted. A black rectangle placed as an annotation can be removed by the recipient. Redact the image first, then convert it to PDF.
6. Watermark the copy so it cannot be reused
When you do have to reveal your full number, the remaining risk is reuse. The fix is a watermark that states the purpose, such as "For ABC Mart part-time hiring only, 2026.11.12". Spread across the image, it makes the copy look suspicious if someone tries to use it for opening a phone line or applying elsewhere.
| Placement | Reuse protection | Readability | Best for |
|---|---|---|---|
| One corner | Low (easy to crop) | High | Not suitable for ID copies |
| Single line in the center | Medium | High | Quick identity checks |
| Tiled, semi-transparent | High | Preserved | ID and bank book copies |
Set opacity around 30–45% so the text stays readable while the watermark is unmistakable, rotate it so the pattern runs diagonally, and keep the text around 4–6% of the image width so messenger compression does not blur it. Order matters: redact first, watermark second, shrink last. If a hiring portal limits upload size, finish with image compression, and if the photo is huge, use image resize to bring it to about 1,200–1,600 px wide.
7. Sending it, and what to do if it leaks
Check that you are in a one-on-one chat, not the store's group chat, before you hit send. If the request comes from a personal email or an unfamiliar number that does not match the job posting, call the company's main line first: fake job offers are a known way to harvest ID copies. Afterwards you can ask HR to delete the copy once filings are done. Article 21 of the Personal Information Protection Act requires personal data to be destroyed without delay once its purpose has been fulfilled or its retention period has ended.
If you suspect a leak, you can check phone lines opened in your name and block new ones through M-Safer (msafer.or.kr), run by the Korea Association for ICT Promotion, and register the exposure in the Financial Supervisory Service's personal information exposure system so that financial companies apply extra checks. Misusing another person's registration number is punishable by up to three years in prison or a fine of up to 30 million won under Article 37 of the Resident Registration Act. Report actual misuse to the police.
8. Frequently Asked Questions (FAQ)
Q1. My manager says not to hide the last digits. Can I refuse?
At the application stage, offer to write the number on the employment contract once you are hired. Once you are hired and insurance enrollment is due, the employer does need the number, so provide it on HR forms or as a watermarked copy.
Q2. Can I send a screenshot of a mobile ID?
Mobile IDs in Korea are designed to be verified through QR codes, so a screenshot carries the same risk as a paper copy. If you must send one, redact and watermark it in the same way.
Q3. Does the photo need to be in color?
Unless the recipient specifies otherwise, black and white is fine. The name and photo must be clear, and a semi-transparent watermark tends to stand out better on a color image.
Q4. Will a watermark make the copy useless to the employer?
No, as long as it does not cover the text so heavily that it cannot be read. It also serves as proof that the copy was issued only for that employer.
9. Stamp "for submission only" on your ID copy
Once the sensitive fields are covered, the last step is writing where the copy is going across the whole image. Open the photo watermark tool, upload the photo, type something like "For ABC Mart hiring only, 2026.11.12", choose the tiled placement, and adjust opacity, rotation and size in the live preview until the copy is readable but hard to reuse. Everything runs in your browser and the photo is never uploaded to a server, so an image containing your registration number never leaves your device.
If the result is too large for a hiring portal, shrink it with image compression. If you are combining several documents into one PDF, see secure PDF merging as well.
