Taxes when changing jobs in Japan
Former-employer certificate, combined adjustment, employment gaps, and final returns.
Give your new employer the former employer’s withholding certificate so they can combine both salaries in year-end adjustment; if there was a gap, a second unadjusted job, or a missing certificate, you file a return to reconcile.
Effective: 2026-01-01 to 2026-12-31
Professional review pending — treat as draft and confirm with the authorities.
Key points
- Hand the former-employer certificate to the new employer promptly.
- A combined year-end adjustment settles both salaries.
- An employment gap can change social insurance and withholding.
- If no combined adjustment happens, file a return with both certificates.
Combining your salaries
When you change employers within a year, the new employer can perform year-end adjustment on both jobs — but only if you provide the former employer’s withholding certificate. That certificate carries your prior salary and withholding so the combined calculation is correct. Request it from the old employer if it does not arrive.
Gaps and returns
A gap between jobs can affect health-insurance and pension enrollment (you may have paid national health insurance and national pension in between), and those premiums are deductible. If the new employer could not combine the certificates, or you had other income, file a return using both certificates. Leaving employment entirely before year-end usually means filing for a refund.
Who this is for
- People who changed jobs this year
- Anyone with a gap between jobs
What this is not
- Cross-border relocation (see the foreign-resident guides)
- Without the former-employer certificate, a combined adjustment cannot be done and you must file.
Frequently asked questions
Do I need to file a tax return in Japan?
Many employees do not, because tax is settled by year-end adjustment (年末調整). You generally must file (確定申告) if you have side income over ¥200,000, two or more employers, self-employment income, sizeable investment or crypto gains, or you want to claim deductions like large medical costs or a first-year mortgage credit. Filing season is Feb 16 – Mar 15 via e-Tax. When unsure, check the NTA guidance or ask a 税理士.