W-8BEN vs W-9 after you move: the one form that decides your US dividend withholding (30% or 10%)

The short version. The form you file is decided by your status, not your address. US citizens and green-card holders always certify on Form W-9, even living in Japan. Nonresident aliens — for example, a Japanese national who worked in the US on a visa and then moved home — certify on Form W-8BEN. A valid W-8BEN with the US–Japan treaty claim in Part II drops the default 30% dividend withholding to 10%. W-8BEN expires after about three years, and a change of address triggers a 30-day re-filing rule. Get it wrong and the brokerage withholds 30% on every US dividend until you fix it.

I’m Jin — a Japanese national who spent four years working in US manufacturing before moving back. I researched the US withholding forms in detail for my own accounts, and I’m not a tax professional. This is my own research from IRS sources, not tax advice. Confirm the specifics against the official IRS pages and a professional before you act.

The one question that decides everything: are you a “US person”?

Almost every mistake I see comes from assuming the form follows your location. It doesn’t — it follows whether the IRS considers you a US person.

You are…	Your form	Why
US citizen (even living in Japan)	W-9	Citizenship never lapses for tax purposes
Green-card holder	W-9	Lawful permanent residents are US persons
Someone who passes the Substantial Presence Test	W-9	Counted as a resident alien
Nonresident alien (e.g. Japanese national back in Japan, no longer meeting the presence test)	W-8BEN	Certifies foreign status + claims treaty benefits
A foreign company or partnership	W-8BEN-E	Entity version — not for individuals

The trap: a US citizen who moves to Japan does not switch to W-8BEN. I’ve seen people assume that leaving the country makes them “foreign” for the brokerage. It doesn’t. They stay a US person and keep certifying on W-9. Filing a W-8BEN when you’re actually a US person is a false certification of foreign status — not a shortcut you want.

If you’re the Japanese-national case — you held a US visa, went home, and stopped meeting the Substantial Presence Test — then W-8BEN is your form. That’s the situation this article is really written for, and it’s the one where the dollars move.

What a valid W-8BEN actually saves you: 30% → 10%

Here’s the money part. Without any valid form on file, the withholding agent — your brokerage or bank, not the IRS — must withhold at the 30% statutory rate on US-source FDAP income: dividends, interest, rents, royalties. That 30% is the default, and it’s automatic.

File a correct W-8BEN and claim the US–Japan treaty in Part II, and the rate on portfolio dividends falls to 10% under Article 10 (as of my research — verify against the current treaty text).

US-source income (Japan-resident nonresident alien)	No valid form	Valid W-8BEN + treaty claim
Dividends (individual/portfolio)	30%	10% (Art. 10)
Interest — most govt bonds, bank deposits	30%	0% (Art. 11)
Capital gains on securities	—	0% US — taxed only where you reside (Art. 13)

Put that in dollars. On $5,000 of annual US dividends, the difference between 30% and 10% withholding is $1,000 a year held back — money you then have to chase through a US tax return to recover. The form takes maybe 15 minutes. Skipping it, or letting it lapse, is one of the more expensive pieces of paperwork you can ignore.

To actually get the 10%, Part II has to list Japan as your country of residence and cite the treaty article. A blank Part II certifies foreign status but claims no treaty benefit — you’d stay at 30%. This is the single most common way people leave money on the table.

If you’re a US citizen in Japan: the treaty doesn’t help you

Worth stating plainly, because this trips people up. The US–Japan treaty has a saving clause (Article 1(4), as of my research) that preserves the United States’ right to tax its own citizens as if the treaty didn’t exist.

A US citizen living in Japan cannot use the treaty to cut US withholding on US dividends. Your W-9 stays on file, standard US rules apply, and the cross-border fix is the Foreign Tax Credit (Form 1116) — not a reduced withholding rate. If that’s you, the W-8BEN discussion above isn’t your lever. Your account and reporting mechanics are closer to what I cover in keeping your US brokerage after moving to Japan and your first tax year after leaving the US.

When you have to re-file (and the 30-day rule that bites)

A W-8BEN isn’t forever. Two clocks run:

• The 3-year clock. A W-8BEN is valid from the signing date through the last day of the third succeeding calendar year. Sign it September 30, 2024 → it’s good through December 31, 2027. After that it’s stale, and the brokerage reverts you to 30% until you renew.
• The 30-day clock. If any information on the form becomes wrong, you must notify the withholding agent and file a new form within 30 days of the change.

What counts as a “change of circumstances” that trips the 30-day rule:

Change	Action
You move (new address — including moving to a US address)	New W-8BEN within 30 days
You become a US person (green card, pass the presence test)	Switch to W-9
You move from Japan to a third country	New W-8BEN — the Japan treaty claim in Part II is now invalid
Change of citizenship/tax residency	New form

That address point matters more than it looks. Updating your brokerage address and refreshing your W-8BEN are two separate obligations — the address change is exactly the event that makes the old form incorrect. I go deeper into the account side of this in changing your brokerage address to a Japan address. Brokerages usually auto-prompt a renewal, but the legal obligation sits with you, not them.

One more edge case: joint accounts. If any joint owner has a W-9 on file, the IRS treats the whole account as a US-person account — that overrides a W-8BEN from another holder. So a mixed US-citizen / nonresident-alien couple can’t get the 10% treaty rate on a jointly-held account.

Where a professional actually earns their fee

The form itself you can usually complete yourself — brokerages walk you through W-8BEN online. Where it gets genuinely hard is the return behind it: reconciling treaty-rate withholding against your Japan filing, claiming a Foreign Tax Credit as a US citizen, or untangling a year where your status changed mid-stream. That’s also where the PFIC rules on Japanese funds can quietly wreck a US person’s tax bill.

If you want one place to start on the US side, Taxes for Expats is a US–Japan expat specialist firm — it’s not the only option, and I’d compare it against others, but it’s a reasonable first call. (Full disclosure: that’s a referral link — it gets you $25 off your first filing, and I may receive a small credit if you file through it.)

FAQ

I’m a US citizen who moved to Japan. Do I switch from W-9 to W-8BEN?

No. Citizenship makes you a US person for tax purposes no matter where you live, so you keep certifying on W-9. Filing a W-8BEN would falsely certify foreign status. Your cross-border relief comes from the Foreign Tax Credit, not treaty withholding.

My W-8BEN is on file — do I get the 10% dividend rate automatically?

Only if you completed Part II claiming the US–Japan treaty (Article 10) and listing Japan as your residence. A W-8BEN with a blank Part II certifies foreign status but claims no treaty benefit, so you’d still be withheld at 30%. Check that the treaty section is filled in, not just signed.

How often do I need to re-file W-8BEN?

It’s valid through the end of the third calendar year after you sign it — so roughly three years. Any change of circumstances (a new address, a move to another country, becoming a US person) requires a new form within 30 days. Brokerages often prompt you, but the responsibility is legally yours.