Flat Tax vs Progressive Scale Comparator

When making a withdrawal from your French life insurance, you can choose between two tax options for your gains:

• PFU (Flat Tax): A flat-rate levy of 30% (12.8% income tax + 17.2% social contributions). After 8 years, the income tax rate drops to 7.5% with an allowance.
• Progressive scale: Gains are added to your income and taxed at your marginal tax bracket (TMI) + 17.2% social contributions. After 8 years, the allowance also applies.

The flat tax is generally more advantageous for marginal brackets of 30% and above. The progressive scale is preferable for 0% or 11% brackets, as the tax will be lower than the flat rate of 12.8%.

To make the right choice between the flat tax (PFU) and the progressive income tax scale, it is essential to understand in detail how each option works and the rules governing them.

The flat tax (PFU) broken down

The flat-rate levy, introduced by the 2018 Finance Act, applies by default to all investment income. It consists of two components:

• 12.8% income tax: This is a flat rate, regardless of your income level. Whether you earn 20,000 or 200,000 euros per year, the rate remains identical.
• 17.2% social contributions: CSG (9.2%), CRDS (0.5%), solidarity levy (7.5%). These contributions are identical regardless of the option chosen.

In total, the flat tax represents 30% of gains. For life insurance contracts held for more than 8 years, a special regime applies: the income tax rate is reduced to 7.5% (instead of 12.8%) for the portion of outstanding balances below 150,000 euros, with a prior allowance of 4,600 euros (single) or 9,200 euros (couple). The overall rate then drops to 24.7% on the portion exceeding the allowance.

The progressive income tax scale

If you opt for the progressive scale, your life insurance gains are added to your other income and taxed according to the following brackets (per share of family quotient):

• Up to 11,497 euros: 0% rate.
• From 11,498 to 29,315 euros: 11% rate.
• From 29,316 to 83,823 euros: 30% rate.
• From 83,824 to 180,294 euros: 41% rate.
• Above 180,294 euros: 45% rate.

When you opt for the progressive scale, your life insurance gains are added to your other income. They are therefore taxed at your marginal tax bracket (TMI), meaning the rate applied to the highest portion of your income.

When is the progressive scale more advantageous?

The progressive scale is more advantageous than the flat tax when your TMI is lower than the flat rate of 12.8%. This applies to two categories of taxpayers:

• TMI at 0%: Your gains are fully exempt from income tax (only the 17.2% social contributions apply). The saving compared to the flat tax is 12.8% of the gain amount.
• TMI at 11%: Your gains are taxed at 11% instead of 12.8%, a saving of 1.8 percentage points. Additionally, by opting for the progressive scale, you benefit from the partial deductibility of CSG (6.8% of deductible CSG), which reduces your taxable income the following year.

Starting from a TMI of 30%, the flat tax is systematically more advantageous for the income tax portion (12.8% vs 30%, 41%, or 45%).

The deductible CSG mechanism

When you opt for the progressive scale, a portion of the CSG paid on your investment income becomes deductible from your taxable income the following year. The deductible CSG rate is 6.8% (out of the total 9.2% CSG).

In practice, if you paid 17.2% social contributions on 10,000 euros of gains (1,720 euros), you can deduct 680 euros (6.8% x 10,000 euros) from your taxable income the following year. The resulting tax saving depends on your TMI: 680 x 11% = 74.80 euros for a TMI of 11%, or 680 x 30% = 204 euros for a TMI of 30%.

This additional advantage is often overlooked in simplified calculations, but it can tip the balance in favor of the progressive scale for TMIs of 11%, and sometimes even 30% when the amounts involved are modest.

Important: when opting for the flat tax, the CSG is not deductible. It is a global tax choice: you cannot combine the flat rate of 12.8% with CSG deductibility.

The choice between the flat tax and the progressive scale requires a comprehensive analysis of your tax situation, as this option applies to all of your investment income for the year in question.

The option is global: beware of the trap

A fundamental and often overlooked point: opting for the progressive scale is irrevocable and global. It applies to all your investment income for the year: interest from taxable savings accounts, stock dividends, capital gains, life insurance gains, and bond coupons. You cannot choose the flat tax for some income and the progressive scale for others.

This means that a choice that is advantageous for your life insurance gains could be disadvantageous for your dividends or capital gains. You must therefore calculate the impact across all your financial income before deciding.

Practical guide by tax bracket

Here is a practical guide based on your TMI:

• TMI at 0%: The progressive scale always wins. Your life insurance gains are exempt from income tax (only the 17.2% social contributions apply) instead of bearing 12.8% income tax under the flat tax. The saving is maximal.
• TMI at 11%: The progressive scale generally wins, especially thanks to the deductible CSG. The saving is 1.8 percentage points on income tax plus the CSG advantage. However, check the impact on your dividends: the progressive scale removes the flat tax advantage of 12.8% on dividends (even though the 40% dividend allowance applies with the progressive scale, you must do the overall calculation).
• TMI at 30%: The flat tax is almost always preferable. The 17.2-point gap on the income tax portion (30% vs 12.8%) is too large to be offset by the deductible CSG. Exception: if your gains are very small and the CSG deductibility on other significant financial income is substantial.
• TMI at 41% or 45%: The flat tax is systematically the winner. Never opt for the progressive scale at these TMI levels, except in very unusual circumstances.

Case study: a saver with multiple financial income sources

Consider Marc, with a TMI of 11%, who received during the year:

• 3,000 euros of life insurance gains (contract over 8 years old)
• 2,000 euros of stock dividends
• 500 euros of fixed-term deposit interest

Flat tax option: The entire 5,500 euros is taxed at 30%. For the life insurance gains, the 4,600 euro allowance applies, leaving 0 euros taxable (3,000 is below 4,600). The flat tax applies to the remaining 2,500 euros (dividends + interest), resulting in 750 euros total tax.

Progressive scale option: The life insurance gains still benefit from the 4,600 euro allowance (so 0 taxable). Dividends benefit from the 40% allowance (taxable base: 1,200 euros) and are taxed at 11%, i.e., 132 euros. Interest is taxed at 11%, i.e., 55 euros. Social contributions of 17.2% apply on the full 5,500 euros (946 euros). But Marc benefits from deductible CSG: 6.8% x 5,500 = 374 euros deductible the following year, saving an additional 41 euros (374 x 11%). Total: approximately 1,092 euros in tax.

In this specific case, the flat tax (750 euros) is more advantageous than the progressive scale (1,092 euros), mainly because dividends and interest weigh in the balance. This example illustrates the importance of the global calculation: even with an 11% TMI, the flat tax can be preferable if your financial income outside life insurance is significant.

The golden rule: always do the full calculation, incorporating all your financial income for the year, before checking the "option for progressive scale" box on your tax return (box 2OP).

The first and most common mistake is forgetting that opting for the progressive scale is global and irrevocable for the year. It applies to all of your investment income: life insurance gains, dividends, interest, and capital gains. Many savers only calculate based on their life insurance gains without measuring the impact on their stock dividends or other financial income. Another classic error is neglecting the deductible CSG, accessible only by opting for the progressive scale: this 6.8% CSG deduction from the following year's taxable income can tip the calculation in favor of the progressive scale for 11% TMIs. Finally, do not confuse your average tax rate with your TMI. Only the marginal bracket -- the rate applied to the highest portion of your income -- determines whether the progressive scale is more or less advantageous than the 12.8% flat rate.