Should you attach your adult child to his tax household?

Question to an expert

I am about to declare my income, is it more advantageous to attach my adult child to my tax household or to let him fill out his own declaration?

Do you have an adult child under the age of 21 or a student child under the age of 25? It can be linked to your tax household for the calculation of your income tax.

His income then increases your taxable income but you earn a half share of the family quotient, or even a share from the third child attached. However, the more the quotient increases, the more the amount of tax decreases.

In the absence of a connection, and if you provide financial assistance to your child in need, you can deduct from your declared income up to 5,959 euros in alimony, including a lump sum of 3,542 euros if you house him all year round. He will declare his income on his side, including pension.

A calculation to do

Connection or deduction of a pension, what to choose? The higher your marginal tax bracket (TMI), the more attractive the deduction of a pension. Because the tax gain linked to the attachment is limited to 1,570 euros per half-share. With an IMR of 30%, the difference between the maximum tax gain linked to the deduction of a pension and that linked to a half-share of the quotient is therefore 218 euros (5,959 euros x 30% – 1,570 euros) . It is 873 euros for a TMI at 41%, 1,112 euros for that at 45%.

Please note, the attachment has an impact on housing assistance, the reduction in tuition fees, the reference tax income, etc. A calculation is required each year.