Tax filing - a few questions

[Viralriver]

So I'm looking to file taxes this by March 15th for the following:

Salary
Furusato Nozei
Mercari sales (2-3m JPY)
Rakuten Shouken

Usually, I wouldn't file, but the existence of additional income due to Mercari is making me think I should. I applied for one stop on furusato nozei, but I heard if I file a kakuteishinkoku, that the one stop becomes null & void.

Questions:

1. Is it a kakuteishinkoku I need to file, or something else?
2. Is it necessary to file anything specific for the furusato nozei, given I have already done the one stop?
3. Is it necessary to do anything for Rakuten, given all investments are either in my 特定口座 or NISA.

I reached out to an accountant who said she'll do everything for 60k. However, if the work itself is actually fairly easy, I don't mind doing this myself. Let me know what you think based on the above, I'd be very grateful!

[adamu]

1. Is it a kakuteishinkoku I need to file?

Yes.

2. Is it necessary to file anything specific for the furusato nozei, given I have already done the one stop?

If you do a tax return, the one stop becomes invalid. Also, the payment method changes, to part income tax, part residence tax (whereas one stop is 100% residence tax).

The bad news is, for the tax return you need to get a certificate from each place you donated to, and if you did one-stop, they don't issue them automatically. It looks like you might have to contact them all individually.

More info here, under ワンストップから確定申告への切り替え（5自治体を超えた、申請漏れ等）
https://www.faq.furusato-tax.jp/faq/sho ... in=default

3. Is it necessary to do anything for Rakuten, given all investments are either in my 特定口座 or NISA.

Not for NISA. You don't need to for 特定口座 either if the tax was paid automatically. I'm not sure of the details, but apparently including it in your tax return can have an effect on the amount. So you could try including it and see if it benefits you or not (and don't include it if not). Rakuten will have issued you with a certificate for the amount of tax paid/due on the Tokutei account, which you can use for the tax return.