NISA & iDeCo

Can My American Husband Open a NISA Account? (Yes, But It's Complicated)

· Yen & Zen
NISA International Couples PFIC

The moment I realized my husband might not be able to open a NISA account was the same week I finally understood what NISA was.

I thought I was being the responsible one. I had filled out the paperwork, picked the investment allocation, and was ready to have The Financial Conversation. What I hadn’t anticipated was a different conversation — with a clerk at the bank, gently explaining that US citizens have a different situation.

The short version

  • Can an American citizen open a NISA in Japan? Technically yes.
  • Will most Japanese brokers let them? Usually no.
  • Is there a realistic option? Yes — Interactive Brokers Japan (as of summer 2025).
  • Is it complicated? Yes. Keep reading.

Why most brokers say no

It comes down to something called PFIC (Passive Foreign Investment Company). If a US citizen invests in a Japanese investment trust (投資信託), the IRS treats it as a PFIC, which triggers punitive tax reporting on the US side.

Most Japanese brokers don’t want the complication, so they simply don’t open accounts for US citizens, or they restrict what can be purchased.

The Interactive Brokers Japan option

From summer 2025, Interactive Brokers Japan (IBJP) began offering NISA accounts. The appealing part: US ETFs are purchasable, which sidesteps the PFIC problem (a US ETF is not a PFIC to a US citizen).

The NISA annual investment limit is ¥3,600,000 (split into ¥1,200,000 for Tsumitate and ¥2,400,000 for Growth), with a lifetime cap of ¥18,000,000.

What we’re doing

We’re still figuring this out. The short version of our plan:

  • Wife (Japanese): standard NISA at a major Japanese broker
  • Husband (American): opening an IBJP NISA to buy US ETFs
  • Both: reporting honestly on both sides (FBAR / FATCA / Japanese tax)

Things we keep reminding ourselves

  • NISA accounts are reportable on FBAR. The threshold is $10,000 in aggregate — and NISA balances count.
  • iDeCo with investment trusts is still a PFIC problem. Cash-holding iDeCo is fine, but investment trusts inside iDeCo trigger the same headache.
  • Consult a tax pro who knows both sides. We did. It was worth every yen.

This is our personal experience, not tax or investment advice. Always consult a qualified professional for your situation.