建议去看一下具体的到账时间是 2019 年 12 月 31 日还是 2020 年 1 月 2日。
如果你用的是 Paynow，钱可以当天到账 CPF；如果你用的是 eBanking，需要一个工作日即 1 月 2 日到账。
IRAS 系统默认按实际到账的日子，所以今年报税的时候，最后一天填补的 CPF 可能没有反应到 IRAS 网站上，无法达到扣税的目的。
有这种情况的伙伴，请打给 CPF 来进行修改，或者登录 CPF 网站，去 My Requests ——> My e-Concierge 来描述一下。
以下是我提交的描述和 CPF 的回答，供伙伴们参考。
所以还是提前一点弄比较好小毛驴自己
就是的 干嘛等最后一天
自动报税ebanking也没问题。
只要23:59pm之前就行。
Thank you for your enquiry of 3 January 2020.
Yes, rest assured that the answer you received from our colleagues are correct. Online cash top-up applications received on 31 December 2019, by 2359hrs, would qualify for tax relief for Year of Assessment (YA) 2020.
Even though the top-up application shows as it is only processed and credited to your Special Account (SA) in January 2020, online top-up applications received by the Board before the above-stated deadline would be eligible for Tax Assessment of YA 2020.
You can also refer to your tax relief eligibility/amount by following the steps below:
1) Click "My Statement" on the left-navigation panel.
2) Under “Section B”, click on "Retirement Sum Topping-Up Scheme Yearly Statement".
3) Click on “Top-Ups Made to Others” and select the relevant period (by default, it would be from year 2019 to 2020).
4) Click “Proceed
我也是怀疑就算我不给 CPF 写信要求，最终 IRAS 也是会算作 2019 年的扣税项目因为当初填补前打给 CPF，那边说只要当天操作就可以。并没有说还要回头联系他们做修改。
但是保险起见，还是听从了新的建议，联系 CPF 明确说一下。
毕竟阶梯税率下，几万块的 CPF 就涉及到几千块的个税减免，数额不少。