2025 Tax Filing Deadline: March 16, 2026

File Your IBKR Taxes in Japan

Interactive Brokers' reports use the wrong calculation method. We fix that.

NTA Compliant Free Preview Takes 5 Minutes

Why Your Broker's Report Won't Work

1. First in First Out vs Moving Average.

Example: You trade X stock
Buy 10 shares @ $150 on 1/1/2024
Buy 10 shares @ $200 on 1/1/2025
Sell 5 shares @ $220 on 1/1/2026 (¥156.73 USD/JPY)
🇺🇸 Your 1099-B (FIFO)
Cost: $150 × 5 = $750 (earliest shares are sold)
Proceeds: $1,100
Gain: $350
What your broker reports
🇯🇵 Japan NTA (Moving Avg)
Avg: ($150 + $200) ÷ 2 = $175
Cost: $175 × 5 = $875
Proceeds: $1,100
Gain: $225
Correct calculation method

2. JPY conversion required for cost basis AND profit/loss.

Continuing from the X stock example above...

1/1/2024 buy: 10 shares × $150 × ¥140.95 = ¥211,425
1/1/2025 buy: 10 shares × $200 × ¥157.71 = ¥315,420
Avg: ¥26,342/share → 5 shares = ¥131,711
1/1/2026 sell: 5 shares × $220 × ¥156.73
= ¥172,403
Broker says: $225 gain
Correct filing: ¥40,692 gain

Report the wrong number and you're risking an audit. Spread this across hundreds of trades and you could find yourself off by a large amount.

See Your Numbers Free

Pay only when you need the details.

Free Preview
¥0
  • Total P/L (JPY converted)
  • Trade counts and date range
  • Symbols traded
  • Sample trades preview
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Full Report
¥14,800
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Everything in Free, plus:
  • Tax category breakdown (譲渡所得, 雑所得, 配当所得)
  • All trade details with exchange rates
  • PDF report with JPY conversion
  • Unlimited access (no expiry)

Ready to file correctly?

Free preview shows your total P/L in JPY