By Dako & Jay
Nearly everything we own has both our names on it. The checking account, the savings, the taxable brokerage. The retirement accounts are the exception, and only because the law insists they belong to one person each. If you asked how we handle money as a couple, the answer would be a shrug: it’s all one pot.
The shrug works because the United States built the pot. “Joint” is an American legal object with rules attached, and I’d assumed those rules treated the two of us the same. They don’t. Then I looked at how Japan would see the same accounts if we ever moved, and found that Japan doesn’t see a pot at all. It sees two people and asks whose money is whose.
This is the post about what we found, and what we’re doing about it.
The pot has two owners, and the US knows which one is foreign
Start with the part that surprised me most, because it’s happening now, not in some future Japan.
Jay is a US citizen. I hold a green card, which makes me a US tax resident but not a citizen, and for gift and estate tax purposes that distinction is enormous. Married citizens can move unlimited amounts between each other with no tax consequence. When the receiving spouse isn’t a citizen, the unlimited marital deduction disappears. In its place sits an annual allowance: $194,000 in 2026, up from $190,000 the year before. Anything above that eats into the giving spouse’s lifetime exemption and has to be reported.
For a joint bank account, the rules are gentler than they sound. Depositing money into an account we both own isn’t a completed gift under the Treasury regulations. The gift happens only when the non-contributing spouse takes money out for their own use. Day to day, that means a joint checking account isn’t quietly generating gift-tax events every payday. It also means the answer to “was this a gift?” depends on a question we’d never bothered to track: who put the money in.
The estate side is where the asymmetry bites. If one spouse dies and the survivor is a citizen, half of any jointly held property goes into the deceased’s estate, no questions about who paid for it. Not a citizen? The rule flips. The entire value is included, except whatever the survivor can prove they contributed. And the marital deduction that lets a citizen inherit everything tax-free doesn’t apply to me unless the assets route through a qualified domestic trust with a US-citizen trustee. The 2026 federal exemption is $15 million, so for most households this is a documentation problem rather than a tax bill. It’s still a problem I hadn’t known we had, and it’s one more reason our estate documents will be rewritten rather than filed away.
Jay here. The $194,000 number reads like the tax code has a preferred spouse, and it isn’t the one who does all the research. The part that gets me is the proof. “Prove what you contributed” is easy for the person whose paycheck is bigger and whose name is on more paperwork. It’s not designed for a couple that pools everything. I’m the citizen in this house, and I don’t want the default rules deciding what Dako gets to keep.
Japan has no pot
Now move the same accounts across the Pacific.
Japanese banks and brokerages don’t offer joint accounts. One account, one name, and that’s the rule at nearly every institution. The idea of marital property that both spouses own in undivided halves simply doesn’t exist in Japanese practice the way it does in an American checking account.
So how does Japan look at our American joint accounts, if we’re Japanese residents holding them? It looks through the joint title to the money underneath. In Japanese tax practice, a jointly named overseas account belongs to whoever funded it. Opening one and depositing into it isn’t a gift. But if the spouse who didn’t fund it withdraws money to buy something for themselves, that’s a gift. Japanese gift tax is paid by the recipient, with an annual basic exclusion of just ¥1.1 million. When the funding spouse dies, the survivor’s share of what they didn’t contribute is treated as passing from the deceased, into the heir-based inheritance system we walked through in the inheritance post.
There’s a carve-out that keeps ordinary marriages functioning: money a spouse provides for living expenses or education, in amounts that are normally necessary, isn’t a gift. The catch is in the verb. If that money gets saved instead of spent, or goes into stocks or property, the exemption evaporates for that portion. A spouse who parks “living expenses” in an investment account has, in Japan’s eyes, received a gift.
Read those two sections back to back and the picture is strange. The US honors the pot but keeps a quiet ledger on which of us is the foreigner. Japan doesn’t recognize the pot, and would ask us to show who contributed what, going back to the beginning. Both systems eventually ask the same question. Only one of them has been letting us not answer it.
Who reports what, to which government
Reporting is the part where mixed-nationality couples get tripped, because the obligations attach to individuals even when the money is shared.
We keep a Japanese bank account, in one name because it can’t be in both, as a pool for trips home. It’s funded from the US through Wise. That account puts us over the FBAR line every year. Once your foreign accounts together exceed $10,000 at any point in the year, each owner of a joint account has to report the full balance, not their half. There’s a way to file once as a couple. It only works if every foreign account the other spouse would report is joint, the report goes in on time, and both of you have signed Form 114a. In our case the Japanese account can’t be joint, so the couple shortcut doesn’t help us on that one. That’s a detail I’d have missed if I hadn’t been the one filing.
Form 8938, the FATCA statement, layers on top with its own thresholds. For a couple filing jointly in the US, that’s more than $100,000 in foreign assets at year end, or $150,000 at any point during the year. Living abroad, those jump to $400,000 and $600,000. The reporting rules for couples deserve their own post, including what happens when you pool a large sum in Japan for a house, and it’s coming later this month.
Then there’s the reporting going the other direction, which almost nobody in the US mentions. When money over ¥1 million moves into or out of Japan, the Japanese bank files a report with the tax office. A larger or unusual transfer can bring a letter asking what it was for. For a couple wiring dollars to a Japan account in one spouse’s name, the honest answer, “it’s our shared money,” is exactly the kind of thing Japan’s individual-ownership system doesn’t have a box for. Living expenses for the trip, yes. Savings for later, that’s a gift on paper.
And if we ever became Japanese residents, one more layer: once a resident’s overseas assets pass ¥50 million, an annual overseas asset report is due. We covered how each of our US accounts would fare under Japanese rules already, and the answer is that they survive, but they get inventoried.
What we’re keeping, and what we’re fixing
We didn’t blow up the joint structure. It’s still the right shape for a couple living in the US, and rearranging accounts to satisfy a country we don’t yet live in would be backwards. What needs work is the layer underneath.
The Japan account stays what it is: a spending pool. Money goes in for a trip and gets spent on the trip. Nothing about it should read as savings in one spouse’s name funded by the other, and after reading the gift rules, I understand why that distinction matters more than the balance does.
FBAR stays an annual ritual, and it can’t be a single filing for us, because the Japanese account is in one name. I do the filing. Before it goes in, Jay sees the list: the accounts, the maximum balances, and who owns what. The form isn’t the only place that information lives.
The estate documents are getting rewritten. That was already on our list, and the contribution rule for a non-citizen survivor is the second reason it’s there. It has two questions to answer. What happens to joint property when the survivor isn’t a citizen, and what Japan would do with the same assets.
And here’s the one I’d push on anyone in our position, whether or not Japan is in your future: start a contribution record. Not every paycheck, but the large deposits into a joint brokerage and which of you they came from, plus any transfer from the citizen spouse to the non-citizen spouse that could brush the annual allowance. Both countries eventually ask who put the money in. A record is an answer. Memory is a guess.
The thing we haven’t done is set up separate accounts for a hypothetical Japan. If we move, the dual-residency mechanics will decide when the Japanese view of our money kicks in, and that’s the moment to restructure, not before.
Jay here, one more time. The honest version of “what we do” is that Dako does it and I look at the result. I don’t read Japanese, so every form on that side of the ocean runs through her. What I can hold is the part that doesn’t need Japanese. I know which accounts exist and I sit in on the decisions. And I’ve come around to a rule I’d have argued with: if one of us can’t answer “whose money is this,” the setup isn’t working. In a marriage that pools everything, that question sounds like an accusation. It isn’t. It’s the job.
FAQ
We’re both in the US. Do we need to change anything about our joint accounts?
Probably not the accounts themselves. What’s worth starting is a record of who contributes what, because the contribution rule for a non-citizen surviving spouse and the Japanese ownership rules both turn on it. Rearranging accounts for a country you don’t live in yet is premature.
Is putting money into our joint account a gift to my non-citizen spouse?
For a joint bank account, not at deposit. Under the regulations, the gift is complete when the non-contributing spouse withdraws for their own benefit. Joint brokerage and other jointly titled property can follow different timing, which is a question for a professional rather than a blog.
Can we file one FBAR for both of us?
Only if all the foreign accounts the non-filing spouse would need to report are joint, the filing spouse files on time, and both of you have signed Form 114a. If either of you has a foreign account in one name, as we do, that person files their own.
Does Japan tax money my spouse sends me for living expenses?
Money used for ordinary living and education expenses from a spouse isn’t a gift under Japanese rules. Money that gets saved or invested instead is, and the annual basic exclusion is ¥1.1 million, paid by the recipient.
What happens if my spouse gives up US residency?
Filing jointly is no longer automatic. A couple can elect to treat the nonresident spouse as a US resident for a joint return, but that pulls both spouses’ worldwide income into US tax and the election is a once-in-a-lifetime choice. Without it, the US spouse files separately or as head of household.
This article is general information about US and Japanese tax and property rules, not tax or legal advice. Gift, estate, and reporting questions for mixed-nationality couples are fact-specific, and cross-border ones especially so. Please work with qualified professionals in both countries before acting, and see our Disclaimer for details.