When a posting to China runs past five years, what happens to social insurance? Extending the certificate of coverage and avoiding double enrollment

Bottom line first: Social insurance for a posting to China is handled under the Japan-China Social Security Agreement (in force 1 September 2019), whose certificate of coverage lets the worker stay in Japan's employees' pension only and avoid double enrollment in China's employees' basic old-age insurance. The agreement covers pension only; it does not include medical insurance. For the first five years from the start of the posting the worker can stay in Japan's system only, but when the posting continues past five years it is not extended automatically. The Japanese employer applies to the Pension Office for a continuation/extension, and only when the relevant authorities of both countries consult and agree is it extended. The extension period is in principle within five years, with room to extend even beyond ten years in total where there are special circumstances. If no agreement is reached, the worker enrolls, in principle, in China's system. The final judgment on coverage is made by the implementing agencies; the residence-status application is the field of a gyoseishoshi (administrative scrivener) and income tax and tax treaties the field of a tax accountant, each contracted separately as an independent business entity where the matter crosses entities.

Why does double enrollment in social insurance arise for a posting to China?

Even when a Japanese company posts an employee to China, as long as the employee keeps an employment relationship of being used by the Japanese company, in principle the insured status under Japan's employees' pension and health insurance remains. In China, meanwhile, an employee is required to enroll in the employees' basic old-age insurance. Without the agreement, pension premiums arise in both Japan and China for the same employee—this is double enrollment and the double burden.

What avoids this is the Japan-China Social Security Agreement, signed in May 2018 and in force on 1 September 2019. The basic idea is to "enroll in the pension system of the country where you work" (the work-location principle), with the exception that for a temporary posting the worker can keep enrolling in the sending country's (Japan's) system only. The agreement covers public pension only; it does not include medical, workers' accident, or employment insurance. The whole picture of this double enrollment is organized in social insurance for a posting to China and Chinese employees — preventing double enrollment under the Japan-China Social Security Agreement. This article narrows to what comes next: when the posting continues past five years.

How many years is the certificate of coverage valid, and when does it expire?

When posting from Japan to China, what certifies that the worker keeps enrolling in Japan's pension system only is the certificate of coverage, issued by the Japan Pension Service. The worker presents it on the Chinese side to obtain exemption from the employees' basic old-age insurance.

Item	Content
Initial enrollment period	For five years from the start date of the posting, the worker enrolls in Japan's pension system only
What the certificate is	Certifies that the employee keeps enrolling in Japan's pension system and that China's employees' basic old-age insurance is exempted
Issuing agency	Japan Pension Service (Pension Office / Service Center)
Workers posted before the agreement took effect	Treated as posted on the effective date, 1 September 2019; for five years from that date they enroll in Japan's system only

The point to note is that the exemption continues for "five years from the start date of the posting," not something decided by the mere length of the expected posting. Even if it was expected from the outset to exceed five years, this framework first covers up to five years, and whether an extension is needed is judged as the five-year expiry approaches. Check the actual application form, filing destination, and processing time against the latest Japan Pension Service guidance just before you apply. For the treatment of injury during overseas work, see also an overseas business trip and an overseas posting are completely different for workers' accident insurance.

How do you extend it when the posting continues past five years?

When a posting continues past five years, the certificate of coverage is not extended automatically. When the period extends due to unforeseeable circumstances and the like, continued enrollment in Japan's system only is allowed only where, on application, the relevant authorities of both countries consult and agree. Without an agreement, there is no extension.

Stage	Treatment
Start of posting to 5 years	Enroll in Japan's system only (initial certificate of coverage)
Extension past 5 years	The Japanese employer (the person themselves, if self-employed) applies to the Pension Office for a continuation/extension. Agreement of both countries' relevant authorities is a condition. The extension period is in principle within five years
Beyond ten years in total	Only where there are special circumstances is there room for a further extension (application and agreement of both countries required)
When the extension is not granted	In principle, enroll in the pension system of China, where the work is performed

The procedure is that, when an extension becomes necessary, the Japanese employer files a continuation/extension application with the Pension Office, and the relevant authorities of both countries judge case by case. If the extension is granted, a new certificate of coverage is issued. An extension is not a matter of right; it rests on an agreement of both countries suited to the individual situation, so once expiry comes into view it is safest to consult the Pension Office early and confirm whether and when to apply. Note that the China agreement has no so-called interval rule (a requirement to leave a certain period before re-posting), but the earlier posting and the re-posting must not be substantively continuous.

If the extension is not granted, what happens to the premiums?

If the extension is not granted, in principle the worker enrolls in the pension system of the country where the work is performed—that is, China's employees' basic old-age insurance. This is because the agreement's exemption is limited to the scope that both countries agree on.

Situation	Japan's employees' pension	China's employees' basic old-age insurance
Extension granted	Continue enrollment	Exempted
Extension not granted	Insured status can remain if the employment relationship continues	Enrollment required

What to watch here is that, even if the extension is not granted, so long as the employment relationship with the Japanese company continues the insured status under Japan's employees' pension itself in principle remains. In other words, when the exemption ends, the Japanese status and the Chinese enrollment overlap, and there is a risk of returning to the double burden. Also, because the agreement covers pension only, China's medical, workers' accident, and unemployment insurance follow the local system regardless of whether the extension is granted. The understanding that "there is an agreement, so nothing need be paid in China" does not hold in the extension phase either.

How is the certificate treated on return home or on switching to local hire?

How the posting ends changes the treatment of the certificate and social insurance. Confusing this leads to mistaking the counterparty for the procedure.

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• Returning home as planned: on returning and resuming work at the Japanese establishment, the worker is treated as an ordinary insured person under Japan's employees' pension and health insurance. The certificate used to obtain exemption on the Chinese side ends its role with the end of the posting.
• The posting is extended: as in the previous section, file the continuation/extension application before expiry and obtain the agreement of both countries. Without agreement, enroll in China's system.
• Switching to local hire (transfer to a local subsidiary): when the employment relationship with the Japanese company is severed and the person is employed by the Chinese local subsidiary, they fall outside the temporary-posting framework, and the premise of the agreement's certificate of coverage collapses. In this case enrollment in China's system is the rule. How to connect it to Japan's pension after transfer varies with the way of thinking in when a foreign employee returns home, what happens to the pension (lump-sum withdrawal payment) and with the individual situation.
• Moving to Taiwan: because there is no social security agreement with Taiwan, the treatment differs entirely even within the same "Chinese-speaking sphere." A move to a country or region with no agreement is organized in social insurance when you hire in Taiwan or second someone to Taiwan.

Applying for, continuing, and extending the certificate of coverage, and organizing the social-insurance status that comes with a posting, are the field of a Shakai Hoken Roumushi. Applying for, changing, and acting as agent for a residence status (work visa) is the field of a gyoseishoshi; the posted worker's income and inhabitant tax, tax treaties, and tax agent are the field of a tax accountant; and the specific handling of social insurance and tax within China rests with a local professional. Where the matter crosses entities, each is contracted separately as an independent business entity, and there is no referral fee. For how social insurance applies by the direction of hiring or posting, see also social insurance for foreigners coming to Japan on an intra-company transfer or secondment.

Frequently asked questions

Q. Even if we know from the start the posting will exceed five years, can we obtain a long certificate of coverage from the outset?
A. First, five years from the start date of the posting is the target. The exemption continues for "five years from the start date of the posting," not a long period issued from the outset based on the expected length. The part beyond five years is granted only where, before expiry, the Japanese employer applies to the Pension Office for a continuation/extension and the relevant authorities of both countries consult and agree. The extension period is in principle within five years. The longer the expected posting, the more we recommend confirming the expiry timing and the timing of the extension application early.

Q. If we file the extension application, is it always granted?
A. No. An extension is not a matter of right; on application, the relevant authorities of both countries judge case by case and grant it where they agree. If no agreement is reached, the worker enrolls, in principle, in China's pension system (employees' basic old-age insurance). Because the extension review criteria and processing time are not decided by a published uniform standard, consult the Pension Office as expiry approaches and confirm whether to apply and the outlook. Whether an individual case qualifies is determined by a qualified professional after a consultation.

Q. The posting will exceed ten years. Can we no longer extend?
A. Not necessarily. The extension period is in principle within five years, but where there are special circumstances, even when the posting exceeds ten years in total there is said to be room for a further extension if there is an application and the agreement of both countries' relevant authorities. However, whether "special circumstances" apply is an individual judgment and is not necessarily granted. It is realistic to also prepare a design premised on enrolling in China's system.

Q. During the posting the worker transferred to the local subsidiary. What happens to Japan's employees' pension?
A. When the employment relationship with the Japanese company is severed and the person is employed by the Chinese local subsidiary, they fall outside the temporary-posting framework, and the premise of the agreement's certificate of coverage collapses. In this case the rule is to enroll in China's pension system, and the insured status under Japan's employees' pension is lost in line with the end of the employment relationship. How to connect the period paid in Japan to a future pension (totalization under the agreement or the lump-sum withdrawal payment) varies with the individual situation, so it is safe to confirm before the transfer.

Basis for this article

• Agreement between the Government of Japan and the Government of the People's Republic of China on Social Security — signed May 2018, in force 1 September 2019. Covers public pension (Japan side = National Pension and Employees' Pension Insurance, excluding each fund; China side = employees' basic old-age insurance). Medical, workers' accident, and employment insurance are outside its scope (effective date confirmed on the Japan Pension Service "The Japan-China Social Security Agreement has taken effect" on 5 November 2026)
• Japan Pension Service, "Systems to enroll in when working from Japan in a country with an agreement" — where the posting period exceeds five years due to unforeseeable circumstances, in principle the worker enrolls in the counterpart country's system, but on application the relevant authorities of both countries may consult and agree to continued enrollment in Japan's system only. The Japanese employer (the person, if self-employed) may apply to extend the exemption period, and agreement of both countries' relevant authorities is required to grant it. Accessed 5 November 2026
• Japan Pension Service, "Country-specific notes (China)" — for five years from the start date of the posting, enroll in the sending country's pension system only. Beyond five years, an extension is possible by the case-by-case judgment and agreement of both countries' relevant authorities on application, with the extension period in principle not exceeding five years. Where there are special circumstances there is room for an extension even when the posting exceeds ten years in total. The China agreement has no interval rule, but the earlier posting and the re-posting must not be substantively continuous. Workers posted before the agreement took effect are treated as posted on the effective date (1 September 2019). Accessed 5 November 2026
• Employees' Pension Insurance Act (Act No. 115 of 1954), Article 9 — a person under 70 who is used by a covered establishment is an insured person of employees' pension insurance. Insured status in principle continues even for overseas work if the employment relationship with the Japanese company continues (confirmed on e-Gov Law Search on 5 November 2026)
• Act on Certified Social Insurance and Labor Consultants (Act No. 89 of 1968), Article 2, paragraph 1, item 1 (preparation of applications, etc.), item 1-2 (agency for filing procedures), item 3 (consultation and guidance)
• The specific enrollment/exemption procedures for China's employees' basic old-age insurance and medical insurance, the operation of presenting and accepting the certificate of coverage in China, and the detail of extension review criteria and processing time rest with the local system and practice and the latest guidance at the time of application. The handling for each company and posting, and whether "special circumstances" apply, are not given a uniform conclusion in this article (unverified)

This article is general information. Individual determinations are made by a qualified professional after a consultation, in light of individual circumstances. 四葉社会保険労務士事務所 can advise on organizing the treatment of employees' pension and health insurance for employees posted to China, supporting the application, continuation, and extension of the certificate of coverage under the Japan-China Social Security Agreement, and organizing social insurance on switching to local hire or transfer. Residence-status applications and agency are handled by a gyoseishoshi, income tax and tax treaties by a tax accountant, and procedures within China by a local professional, each as an independent business entity contracted separately, with no referral fee. Fees are set out in the fee schedule, and frequently asked questions in the FAQ. Written by Joji Uramatsu (Shakai Hoken Roumushi, Gyoseishoshi, Registered Real Estate Transaction Specialist).