US ↔ Japan money, from someone who lived it.
I'm Jin — a Japanese national who spent four years working in the US. Most money guides are written for people staying put. This one isn't. Here I work through the cross-border problems that don't get covered well anywhere: keeping a US brokerage after moving to Japan, the phone/2FA trap, PFIC, cross-border tax — from my own research and real numbers, not generalities.
One person's record — not investment or tax advice. Rules vary by firm, account, and timing.
401(k) and IRA after moving to Japan: leave it, roll it, or cash out?
Understand your US 401(k) and IRA options when moving to Japan: leave in place, roll over to IRA, or cash out—each with different tax and withdrawal implications.
Your first tax year after leaving the US: dual-status returns, FBAR, and the $10,000 line most people miss
US tax obligations when leaving mid-year: dual-status filing status, FBAR requirements at $10k threshold, Form 8938 disclosures, and state tax tail risk.
Changing your brokerage address to Japan: what actually happens at Schwab, Fidelity, and Vanguard
What happens when you change your US brokerage address to Japan. Account restrictions, fund purchase limits, and the safest sequence before leaving.
Google Voice vs a real US number for bank 2FA: why free sometimes fails at the worst moment
Google Voice keeps a US number alive for free — so why do some banks refuse to text it? How VoIP detection works, how to test your own accounts before you leave the US, and when a $5 real number is the safer anchor.
Porting your US phone number before you move abroad: keep it for about $5/month
Keep your US phone number when moving abroad by porting to an MVNO before you leave. Essential for 2FA and banking access. Costs about $5/month.
Can you keep your US credit cards after moving to Japan? The address, payment & login reality
Moving from the US to Japan and want to keep the US cards you spent years building? They don't auto-close — but three things get in the way: a US address, a US bank to pay from, and the SMS 2FA that dies with your US number. Here's the real picture.
NISA and US citizens: why Japan's tax-free account can be the opposite for you
NISA is a great deal for most residents of Japan — but if you're a US citizen or green-card holder, it can quietly become the worst of both worlds: still taxable to the IRS, and usually holding PFICs. Here's why, and what to weigh.
PFIC: why Japanese mutual funds (and NISA) can be a tax trap for US persons in Japan
If you're a US citizen or green-card holder living in Japan, that eMAXIS Slim fund or NISA holding can be a PFIC — taxed by the IRS at punitive rates with a yearly Form 8621. Here's what PFIC is, why it's so brutal, and what US persons actually do about it.
Keeping a US phone number after you leave: the 2FA problem nobody warns you about
Move abroad, your US SIM dies, and suddenly you can't log into your bank, brokerage, or credit cards — the 2FA code goes to a dead number. Here's what actually breaks, why VoIP isn't enough, and how to keep a real US number for a few dollars a month.
Can you keep your US brokerage after moving to Japan? I compared Schwab, Fidelity, Vanguard & IBKR
Moving from the US to Japan and wondering if your US brokerage survives the move? A first-hand comparison of Schwab, Fidelity, Vanguard and IBKR — the 'held but frozen' trap, the US-address myth, the 2FA problem, and how to open an escape hatch before you go.