Tax on gains and dividends, loss deductions, product limits, recordkeeping, and asset-location strategy.
NISA exempts qualifying gains and dividends from Japanese tax but caps contributions and gives no loss deduction; a taxable account has no cap and allows loss offsets and three-year carryforward but taxes gains at 20.315% — so put growth assets in NISA and loss-sensitive strategies in the taxable account.
The headline difference is tax. In a taxable account, gains and qualifying dividends on listed securities are generally taxed at 20.315%. In NISA, those qualifying returns are exempt from Japanese tax — the wrapper’s core benefit, most valuable for assets you expect to grow a lot over a long period.
But taxable accounts have one advantage NISA lacks: loss relief. Taxable losses can offset eligible gains and dividends and, when you file, carry forward three years. NISA losses give no deduction and cannot be carried forward, so a strategy that relies on realising losses belongs in a taxable account, not NISA.
NISA is limited by statute and by your broker’s menu — only eligible products, and only up to the annual and lifetime allowances. A taxable account has no contribution ceiling and a broader product scope, so it naturally holds anything beyond NISA limits or ineligible for NISA.
On records, NISA is simple domestically (no Japanese tax to compute), while a specified account with withholding simplifies taxable filing by having the broker calculate and withhold. Keep annual transaction reports either way, especially if you use multiple brokers or hold foreign assets.
Because the accounts have opposite strengths, where you place each asset matters. The efficient default is to hold assets you expect to produce positive long-term returns inside NISA — using the tax-free space where it does the most good — and to place overflow, NISA-ineligible assets, loss-sensitive strategies, and active trading in the taxable account, where loss offsets exist.
Example: a broad long-horizon equity fund is a natural NISA holding, while a strategy where you might realise losses to offset other gains belongs in the taxable account. Most investors fund NISA first, then use a specified account for the rest.
Brokerage (NISA/iDeCo) · Rakuten Securities
A leading low-cost brokerage for NISA and index-fund investing, integrated with Rakuten points and Rakuten Bank.
Fees: Many domestic funds and trades are low- or no-commission — verify current fee schedule.
Brokerage (NISA/iDeCo) · SBI Securities
Japan’s largest online brokerage by accounts, with a very broad low-cost fund lineup and full NISA/iDeCo support.
Fees: Many trades and funds are low- or no-commission — verify current fee schedule.
Brokerage (NISA/iDeCo) · Monex
An established online brokerage often chosen for US-stock access and research tools, with NISA and iDeCo support.
Fees: Commissions vary by product; some funds/trades are low-cost — verify current schedule.
This is education, not a recommendation. Most beginners research low-cost, broadly diversified index funds — for example all-country (全世界株式) or S&P 500 trackers — rather than picking individual stocks, because low fees and diversification are within your control while returns are not. Understand that values fall as well as rise, match the risk to your time horizon, and never invest money you may need soon.