What is NISA?
NISA is Japan's tax-advantaged investment account, modeled after the UK's ISA system. Under the new NISA system launched in 2024, investors can contribute up to 3.6 million yen annually with a lifetime limit of 18 million yen. All capital gains and dividends within the account are permanently tax-free, compared to the standard 20.315% tax rate.
The size of the exemption is easiest to see in money. On a profit of 1 million yen a taxable account hands about 200,000 yen to the tax office, while a NISA account keeps the whole 1 million yen. The design is not original to Japan: it was modelled on the British ISA, which began in 1999 and is widely regarded as having moved household money out of deposits and into markets. Japan copied the intent as well as the shape, and the stated policy aim since 2014 has been the same shift from saving to investing.
NISA Account Structure
The new NISA has two tiers: the Tsumitate (accumulation) tier allows up to 1.2 million yen annually for approved index funds and balanced funds, while the Growth tier allows up to 2.4 million yen annually for a broader range of stocks and funds. Both tiers can be used simultaneously, and the tax exemption has no time limit.
A concrete plan shows the scale. Paying 100,000 yen a month - 1.2 million yen a year - into the accumulation tier at 5% a year fills the 18 million yen lifetime quota in 15 years and leaves a balance of roughly 26.72 million yen. The gain of about 8.72 million yen would have cost some 1.77 million yen in tax elsewhere, and here it costs nothing. The quota is also reusable: sell a holding and the room it occupied comes back the following year, which makes the account far more flexible than the old accumulation NISA at 400,000 yen a year for 20 years.
NISA and iDeCo - Which to Fill First
The usual order is iDeCo first, for the income deduction it gives, then the accumulation tier of the NISA, and the growth tier with whatever is left over. That order reverses when a large expense is in sight. A house deposit or school fees within the next few years should sit in a NISA, because an iDeCo balance cannot be touched until 60 and no exception is made for need. Where liquidity matters, the smaller tax break on more accessible money is the better trade.
Key Considerations
NISA should be the first account most Japanese investors fill because the tax savings are substantial. On a 10 million yen gain, you save over 2 million yen in taxes. However, losses in NISA cannot be used to offset gains in taxable accounts, so it is best suited for long-term, diversified investments rather than speculative trades.
The most common misconception is that investing through a NISA cannot lose money. The account changes how gains are taxed; it does nothing to the investment itself. A fund bought inside a NISA falls exactly as far as the same fund bought in a taxable account. In one respect the loss is worse: a loss realised inside a NISA cannot be set against gains made elsewhere, and it cannot be carried forward, so the tax system offers no consolation at all.
The second practical point is that the account is singular. One person may hold one NISA account, the provider can be changed only on a yearly cycle, and holdings already bought cannot be moved to the new provider - they stay where they are and keep their exemption there. That makes the initial choice unusually durable, so the range of funds on offer, the fees and the ordinary usability of the site are worth comparing carefully before opening rather than after.
Pros, Cons and How the Quotas Are Used
The strength of the account grows with the size of the gain, because what is waived is a percentage. Filling the 18 million yen lifetime quota and holding it at 5% a year for 20 years produces a gain of about 29.74 million yen, on which the tax waived comes to roughly 6.04 million yen - more than a third of the amount originally invested. Unlike a pension arrangement the money is not locked, so this is a large tax break attached to capital that remains available.
The weaknesses are the absence of loss offsetting and the ceiling itself: an investor with substantial assets will find 18 million yen too small to hold everything worth holding. The common shape of use is a monthly purchase of a global equity index fund in the accumulation tier, with the growth tier kept for individual shares or high-dividend ETFs where a more active choice is being made. Unused quota is not carried anywhere, so filling it early rather than late is the rational default.
How the Scheme Evolved
The scheme started in 2014 with an annual quota of 1 million yen and an exemption lasting five years. The quota rose to 1.2 million yen in 2016, and 2018 added the accumulation NISA at 400,000 yen a year for 20 years. Against the British original the result looked cramped - a small allowance with an expiry date attached - and the complaint that it was awkward to use was widely made and largely fair.
The 2024 reform answered that criticism rather than trimming it. The exemption became permanent, the lifetime quota rose to 18 million yen, and the two tiers may now be used together, which puts the scheme within reach of the British ISA. It sits at the centre of policy aimed at moving household money out of savings and into investment. The reason is arithmetic: of some 2,100 trillion yen of household financial assets as of 2024, around 1,100 trillion yen still sits in cash and deposits.