Article 126(1) of the National Pension Act makes a foreign national employed at a covered workplace or residing in Korea a compulsory subscriber, subject to a reciprocity proviso: it does not apply where the person’s home country does not extend its corresponding pension scheme to Korean nationals.
Pension coverage is compulsory — but the exception is in the statute
The question we hear most from companies hiring their first foreign employee is whether social insurance applies. Article 126(1) of the National Pension Act provides that a foreign national employed at a covered workplace or residing in Korea becomes, notwithstanding Article 6, a workplace or regional subscriber as a matter of course, unless excepted by Presidential Decree. The default is coverage. But the proviso to the same paragraph matters: "this shall not apply where the home country of the foreign national does not apply, to nationals of the Republic of Korea, a pension corresponding to the National Pension under this Act." That is reciprocity. If the employee’s home country does not extend its pension to Koreans, Korea does not apply the National Pension either. Two foreign employees doing the same job at the same workplace can therefore differ in coverage by nationality. Checking nationality at hiring is not a mere HR formality but a precondition for calculating contributions. Which countries fall outside reciprocity needs individual verification, as does the separate category excepted by Presidential Decree.
Health insurance is built on different conditions
Health insurance is structured differently. Article 109(2) of the National Health Insurance Act provides that an overseas Korean or foreign national staying in Korea becomes an employee subscriber where they are an employee, public official or teaching staff member of a covered workplace, do not fall within the statutory exclusions, and are registered under the Resident Registration Act, have reported a domestic place of residence under the Act on the Immigration and Legal Status of Overseas Koreans, or have completed alien registration under the Immigration Act. Paragraph (5) of the same article excludes cases such as an approved opt-out where equivalent medical coverage is available under foreign law or insurance, so exclusions have to be checked separately. The test here is registration status, not reciprocity. It is also worth noting that the provision treats overseas Koreans and foreign nationals together as "foreign nationals staying in Korea". In practice, hiring documents must confirm not only visa status but whether resident registration, a domestic residence report or alien registration is in place. Because pension turns on reciprocity while health insurance turns on registration, the two can reach different conclusions for the same employee.
Late entitlement management returns as retroactive contributions
Payroll is fundamentally about managing entitlements rather than calculating figures. Every hire and leaver brings acquisition and loss filings across the four insurances, and a late or missing filing returns later as retroactive contributions and reconciliation. Foreign employees add one more variable, because a change of visa status or the expiry of a period of stay can change eligibility mid-employment. We recommend maintaining nationality, visa status, expiry date of stay and registration status together in the employee register. With those four columns present, changes in entitlement are visible in advance, and the same record carries through to payroll, withholding and year-end settlement.
The purpose of bookkeeping is explainability, not numbers
Treating monthly bookkeeping as "making the ledgers agree" is doing half the job. Expenses are disallowed on audit not usually because the transaction did not happen but because nothing explains it. Foreign companies carry many transactions that do not fit the standard Korean voucher pattern: head-office invoices, overseas card payments, foreign-currency remittances, costs of head-office staff visiting Korea. Unless the documentation rule is set when such a transaction occurs, substantiating it years later becomes close to impossible. Article 81-6(2) of the Framework Act allows a regular audit where the Commissioner, analysing compliance periodically using assessment data, tax information and accounting-integrity material such as external audit opinions, finds indications of non-compliance. This month’s bookkeeping quality connects directly to audit risk years out. We set an account-by-account list of which voucher to obtain and when, and report what is missing against it at each month-end.
The deadlines that come round each year
A foreign company’s annual tax calendar moves on three axes. First, VAT: filed and paid within 25 days after each preliminary period ends (1 January–31 March and 1 July–30 September), and the final return within 25 days after each taxable period ends — four 25ths a year. Second, corporate tax: filed within three months from the last day of the month in which the fiscal year ends, at 10% up to a base of KRW 200m, 20% over 200m to 20bn, 22% over 20bn to 300bn and 25% above 300bn. Companies on a parent’s non-December year-end frequently misread that starting point. Third, payroll and social insurance: monthly withholding returns and payments, contribution reconciliation, and year-end settlement early in the year. Those three sets of deadlines are scattered across different dates, so without an annual calendar built in advance, time leaks away at the same point every month.