RetireJapan

I'm paying a monthly amount to my ex-wife as child support (she has the shinken and my child is living with her).
Is it possible to get a tax reduction by declaring this amount somewhere in my kakutei shinkoku ?

No, you cannot get a tax deduction on the payments, but you can list the child as your Dependent for which you can claim the Dependent Allowance of Y380,000 (Y630,000 yen if the child is a student between 19 and 23), but she will then not be able to claim the Dependent Allowance for the child against her income. Only one of you can claim the deduction...

Thanks @Tkydon.
Actually, she's been on and off from work, part time at best.
Is there a kind of minimum income level, under which claiming the Dependent Allowance is not allowed or not meaningful anymore ?
Extreme example, imagine she received only 200,000 JPY as 2023 salaries, if she declares the Dependent Allowance, would the tax office reiumburse her 180,000 JPY ??
I guess she doesn't have to declare as a taxable income the child support I pay to her, right ?

Hiroshi wrote: ↑Wed Feb 07, 2024 8:00 am Thanks @Tkydon.
Actually, she's been on and off from work, part time at best.
Is there a kind of minimum income level, under which claiming the Dependent Allowance is not allowed or not meaningful anymore ?
Extreme example, imagine she received only 200,000 JPY as 2023 salaries, if she declares the Dependent Allowance, would the tax office reiumburse her 180,000 JPY ??
I guess she doesn't have to declare as a taxable income the child support I pay to her, right ?

At her income level it is probably not meaningful.

If she claims the Dependent Allowance, it would reduce her Total Taxable Salary by Y380,000, which would reduce the tax payable by the rate of her marginal income tax rate. No Taxable Salary, no saving...

Probably 5.105% Marginal Tax Rate

Saving = (1 / (1 - Marginal Tax Rate)) - 1 x Y380,000
= 1 / 94.895% - 1 x Y380,000
= 1.0538 -1 x Y380,000
= 0.0538 x Y380,000
= Y20,440 Tax Saving


For you, it will depend on your marginal tax rate...
(Depending on Tax Band.... 5.105%, 10.21%, 20.42%, 23.483%, 33.693%, 40.84%, or 45.945%... if the amount falls within a single band...)

Therefore,

5.38%, 11.37%, 25.66%, 30.69%, 50.81%, 69.03% or 85.00%...

of the Y380,000 will be refunded (or not deducted), and you'll have a slight reduction in Residents' Taxes and Health Insurance Premiums...

Reduction = (1 / (1 - Marginal Tax Rate)) x Y380,000 x 10%

= 1.0538 x 10% x Y380,000
= 0.10538 x Y380,000
= 40,050

For each of Residents' Taxes and Health Insurance Premiums.

If you are supporting her, you can probably also claim her as a dependent...

Thanks a lot @Tkydon for such detailed explanation.