TLDR: SBI are cancelling all Tsumitate setup to use all your allowance in January. Make sure to set it up again in January.
So it seems like SBI is going to make it a little bit harder to use bonus to max out your yearly tsumitate NISA allowance.
They have announced that the formula for determining the maximum bonus you can set for Tsumitate NISA is as follows (assuming monthly tsumitate):
1.2M - (Monthly amount x 12)
Now, the normal thing a lot of people here do is 100 yen so in this case if you set 100 in January, the bonus limit is:
1.2M - (100 x 12) = 1,198,800
which is normal (even Rakuten would do this).
What has changed is if you don't do it in January. Assuming you start in April with 100 a month, the calculation for the maximum bonus stays the same so your tsumitate NISA for the year can only ever hit 1,199,700 (900 + 1,198,800).
In the grand scheme it's not that big of a change but it's clear brokers are taking steps to discourage the gaming of the bonus system. In fact SBI explicitly say this:
本サービスでは、定期的な積立の設定金額にかかわらず、つみたて投資枠の年間投資上限である120万円までの追加買付設定を受付けております。 このたび、長期・積立・分散投資による資産形成を後押しする制度の趣旨に鑑み、2025年1月（予定）に以下のとおり「ボーナス月の積立設定」の上限金額を引き下げる仕様変更を実施いたします。
In consideration of the purpose of the system to support asset formation through long-term, distributed, and diversified investment, we will implement a specification change in January 2025 (scheduled) to lower the upper limit of the "bonus month savings setting" as follows.
