A device presented as simple, but which is not always very readable. To reduce your tax bill, the retirement savings plan (PER) is actually quite easy to use: you simply deposit your savings into it, and the total amount paid over one year can be deducted from your taxable income. You are thus taxed on a smaller amount, which ultimately generates a tax saving!
This is for the theory, but in practice, how to estimate the tax rebate actually obtained? To help you see things more clearly, and act before December 31 – the deadline for making payments deductible from your 2025 income – the neobank Green-Got, which has just launched its PER in partnership with the Garance mutual insurance company, has put a very useful simulator online.
First check that you are at least in the TMI at 30%
To better understand the tax operation of a PER, simply enter your net salary income for this year, for example: 35,000 euros. With the flat rate deduction of 10%, your actual taxable income is therefore 31,500 euros. First lesson: you can thus know your marginal tax bracket (TMI), that is to say the tax rate which applies to the highest bracket of your income. With a net taxable income of 31,500 euros, this TMI is 30%. The latter actually starts from 29,316 euros this year, so you have 2,184 euros of income in this one.
And that’s good news: we consider that the PER becomes fiscally attractive from a TMI of 30%. Below that, this benefit may be deemed insufficient to justify tying up your savings until retirement. To know how much you can pay, I then need to know your PER ceiling. In other words, the amount that allows you to benefit from the maximum tax reduction. The general rule is that you cannot subtract more than 10% of your income taxable thanks to the PER.
You do not directly reduce your tax, but your taxable income
Thus, for an annual income of 31,500 euros, your ceiling for the year will be 3,150 euros. Which is lower than the “floor” for the year, which is 4,637 euros. Each year in fact, a floor and a ceiling (37,094 euros this year for employees) are defined. If 10% of your income is less than the floor, you are entitled to deduct at least up to it. Your 2025 ceiling is therefore 4,637 euros for income of 31,500 euros.
Last step: visualize what your payments – between 100 and 4,637 euros – will generate in tax reduction. Here, by paying a total of 4,637 euros this year to your PER, your tax savings are estimated at 925 euros in 2026: “your tax will go from 2,615 euros to 1,690 euros”reveals the simulator. Indeed, as the latter rightly points out: “Attention common misconception: by placing 4,637 euros in a PER, you do not reduce your tax by 4,637 euros. In reality: you reduce your taxable income by 4,637 euros.”
You can find out the amount not to exceed to maximize your tax rebate
But the great advantage of this simulator is being able to visualize how much you can pay without going out of your highest tax bracket. Indeed, to maximize your tax exemption, it is advisable to pay only the sum sufficient to “neutralize” your TMI. Because below that, the tax savings become less attractive. The same payment of 1,000 euros, for example, generates 300 euros less tax in the 30% bracket, 410 euros in that at 41% and 450 euros in the highest at 45%, against… 110 euros only in that at 11%.
Also, still for a payment of 1,000 euros, with 500 euros available in your 30% tranche, it will be more interesting, for example, to pay only 500 euros the first year, and 500 euros the following, rather than 1,000 in one go the first year. In the first case, you generate 300 euros of tax savings in total, in the second – as half of the payment passes into the 11% bracket – it only amounts to a total of 205 euros.
Finally, the simulator allows you to take into account a multitude of possible incomes (property income, non-salaried income, retirement pension, etc.), your other tax credits and reductions (Pinel, donations, crèche, etc.), and your number of tax shares. You can also view what your payment could generate when your PER expires. My 4,637 euros invested this year, for example, could become 17,367 euros in 30 years, if I aim for a reasonable target return of 4.5% per year.
