What
The SBI Securities Tax Calculator is a free automation tool designed to calculate taxes for users of “Ippan Koza” accounts.
Those using “Ippan Koza” accounts are responsible for calculating and reporting their earnings to the tax authorities each year.
Why
SBI Securities provides CSV and PDF data of trades, but no calculation for taxes. These files are also often inconsistent and may lack information depending on your needs. In short, this software:
- Provides profit & loss calculation to understand your tax liabilities
- Can be used to verify your own tax calculations
Why Ippan Koza in the first place?
Ippan Koza Merit 1: You retain more capital throughout the tax year, allowing you to maximize profits. This is particularly beneficial if:
- Your trading account is large
- You have multiple trading accounts
- You trade frequently
Ippan Koza Merit 2: Avoid paying unnecessary taxes.
If your total annual trading profit is less than 200,000 yen, you’re not required to pay taxes. However, in automatically taxed accounts, taxes are deducted from every sale—regardless of yearly profit. Reclaiming this tax requires additional steps, which can be avoided by using “Ippan Koza”.
How
SBI CSV → Google Sheet
- Download your trade data in CSV format via the SBI trading portal (~5 min).
- Make a copy of Google Sheet (~5 min).
- Paste CSV data into your Google Sheet and run the provided script (instructions are included in the Sheet) (~5 min).
Download
Link
(Note: Requires a Google Account to use Google Sheets)