Moving between the US and Japan: the complete money guide

The short version. The day you leave the US, three things change at once — your US mailing address, your US phone number (the one your banks text 2FA codes to), and your tax status — and almost every US account you own depends on at least one of them. The single biggest thing you can do is sequence it before you go: keep a real US cellular number live, lock in a US street address, and tell your brokerages and banks on your terms rather than getting flagged automatically. US citizens have one extra trap: Japan’s tax-free NISA and nearly all Japanese mutual funds are treated as PFICs by the IRS, so they’re taxed harshly even though Japan leaves them alone. This page maps the whole thing and points you to each piece.

I’m Jin. I moved from Japan to the US for four years of manufacturing work and researched the money side of the move first-hand — I’m not a licensed advisor, so treat everything here as my own research and experience, and confirm the specifics against official pages and a professional.

Where to start

Pick the row that sounds like you.

1. Your US phone number and 2FA — why logins break first

This is the one that breaks before anything else. US banks, brokerages, and credit card issuers push one-time codes by SMS to a US mobile number. Let that number lapse and you can be locked out of accounts whose address you haven’t even touched yet — and reactivation often requires the same dead number to verify your identity, a perfect circular trap.

The critical fork is VoIP versus cellular. Google Voice is the popular free workaround (about a $20 one-time port-in fee), and it carries many 2FA flows — but some banks and brokerages reject VoIP numbers outright because they check for a real carrier. A budget cellular MVNO like Tello (plans from ~$5/month, eSIM supported) keeps a live cellular number that passes those carrier checks. My wife already runs on Tello in the US; once we move back to Japan, my plan is to stay on Tello and keep my US number active — because every account I own is tied to that number, and losing 2FA access would be critical.

(Full disclosure: the Tello links here are a referral — you and I each get $10 in Tello credit if you sign up through them. I’d point to Tello regardless; the credit doesn’t change the advice.)

Timing matters: Google Voice porting needs an active US SIM at the moment you port, so it has to happen before you leave. Details in porting your US number before moving abroad, the Google Voice vs. a real US number for 2FA comparison, and the full playbook on keeping a US phone number for 2FA after leaving.

2. Your US address — what breaks when you change it

Under the USA PATRIOT Act, banks and brokerages have to verify where you physically live. The moment you update your address of record to a foreign country, automated compliance systems can flag the account — restrictions, declined cards, or in some cases closure. Your address quietly drives four things at once: brokerage residency for securities-law compliance, bank compliance, credit-card billing-address matching on purchases, and where the IRS mails your notices.

P.O. boxes won’t save you — most major institutions reject them, and some commercial mailbox services too. Virtual mailbox services (Anytime Mailbox, US Global Mail, and similar) give you a real street address that many — not all — institutions accept; a few explicitly forbid mail-forwarding services in their terms. Leaving a stale US address on file is what a lot of expats do as a temporary bridge, but it isn’t harmless: it can amount to misrepresenting your address to the institution, and a foreign IP at login can give you away regardless.

So the address question isn’t “can I hide it” — it’s “which accounts can survive a foreign address, and which need a US one on file.” Work through it per account in changing your brokerage address after moving to Japan and using US credit cards without a US address.

3. Brokerage and retirement accounts — who lets you stay, who forces you out

Brokerages differ enormously, and the trigger is usually the address change to a non-US country. Here’s the rough landscape:

Retirement accounts are more forgiving: a 401(k) or IRA can generally be kept while you live abroad. You just can’t make new IRA contributions without US-source earned income (or income not excluded under the FEIE), and the move alone doesn’t force distributions. I have a 401(k) with an employer match and I plan to leave it invested in the US after I return to Japan — my own biggest worry, honestly, is simply whether I can keep the account open as a non-resident.

Full detail in keeping your US brokerage when moving to Japan and what happens to your 401(k) and IRA after moving to Japan.

4. Credit cards and banks — keeping them alive, getting back in

Good news first: US credit card issuers usually don’t close an account just because you moved abroad. The real risk events are updating the billing address to a foreign one, a failed payment, or inactivity-triggered closure. Some cards require a US billing address in their terms (American Express has been cited); others (Chase Sapphire, Citi) tolerate foreign addresses in practice.

Bank accounts are riskier than cards — Chase and Bank of America have both been documented closing accounts with foreign addresses, while Schwab Bank and Navy Federal come up most often as expat-friendly. The nightmare scenario is the circular lock-out from section 1: a fraud flag declines your card abroad, reactivation needs a call to US customer service, and that call wants a code sent to your dead US number. Getting back in typically takes a live US number plus a US mailing address, and sometimes a branch visit or notarized mailing — hard from Japan.

Watch the cost of moving money, too: wiring USD from a Japanese bank to a US account usually stacks a sending fee (~¥2,500–¥4,000) on top of a correspondent/receiving fee ($15–$25) — confirm your own bank’s current schedule. Playbooks: keeping US credit cards after moving to Japan and getting back into a US bank when you’re locked out from abroad.

5. Tax — the year you move, and the PFIC trap

US citizens never stop filing: if your income tops the threshold ($15,750 single / $31,500 married-filing-jointly for 2025 — verify the current year), you file no matter where you live. Living abroad gets you an automatic extension to June 15 to file, but tax owed is still due April 15, with interest running from then. The year you actually move is often a messy “dual-status” year — resident for part, non-resident for the rest — and you can’t take the standard deduction on that return. Two tools soften the double-tax hit: the Foreign Earned Income Exclusion (up to ~$130,000 of foreign earned income for 2025) and the Foreign Tax Credit (a dollar-for-dollar credit for Japanese tax paid, often better for higher or passive income).

Now the trap that gets US persons in Japan. Japan’s NISA is tax-free in Japan — but the IRS treats the underlying Japanese investment trusts as PFICs, and the Japanese exemption means nothing for US tax. PFIC taxation is punitive (excess-distribution rules plus interest), and you file Form 8621 for each holding, every year. The clean fix is holding US-listed ETFs at a US brokerage instead.

If your return is genuinely dual-country, one place to start is a US–Japan expat specialist like Taxes for Expats (the link takes $25 off a first filing) — it’s one option, not the only one, and I’d still confirm anything important against the IRS pages. (Disclosure: that’s a referral link; I get a small credit if you file through it.)

Go deeper in your first tax year after leaving the US, NISA and US citizens, and PFICs and Japanese funds for US persons.

This one is personal: before I moved, I had to sell the mutual funds I’d been building in my NISA — a gut-punch at the time, though in hindsight it pushed me somewhere better.

FAQ

What should I do first if I’m still in the US?

Lock down your phone number before anything else, because it gates every other recovery path. Keep a real US cellular number live, decide on a US mailing address, and notify (or at least map) each brokerage and bank before you fly — restrictions are far easier to prevent than to reverse. Start with porting your US number before moving abroad.

Can I just keep my old US address on file?

Many expats do it as a temporary bridge, but it isn’t risk-free — it can count as misrepresenting your address, and a foreign login IP can expose it anyway. It’s a stopgap, not a plan; work out per account which ones actually tolerate a foreign address in changing your brokerage address after moving to Japan.

I’m a US citizen — can I invest through NISA in Japan?

You can open one, but for US tax purposes the underlying Japanese funds are almost always PFICs, which erases the Japanese tax break and adds annual Form 8621 filing. Most US persons are better off holding US-listed ETFs at a US brokerage. See NISA and US citizens — and remember this is my research, not tax advice, so confirm with a professional.