A household that owes no tax loses with the flat-rate payment: it hands over 1%, 1.7% or 2.2% of its turnover, where the standard scale asked it for nothing. You will know straight away if that is your case.
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It sets two figures: the share of your turnover the tax office treats as expenses and does not tax (the allowance), and the rate of the versement libératoire, the flat-rate option you can choose instead of the standard progressive scale.
Information verified on October 16, 2026. Indicative calculator with no legal force. The figures it applies are taken from official sources and dated: only your tax notice and the tax authorities are binding.
The official pages where we read the rules and amounts applied here.
From one regime to the other, you do not pay the same amount.
This is what costs the most. The scale starts at zero: a household below the taxable threshold pays nothing. The flat-rate option takes its percentage on every receipt, the first one included. A micro-entrepreneur starting out, whose household is not taxable, therefore pays a sum the scale never asked for.
If your household earns a salary alongside, it pushes the total into the higher brackets and the flat rate quickly wins. One caveat: your turnover leaves the taxable base but is still used to set the rate applied to that other income. That is the effective rate rule, and forgetting it makes the gain look twice as large as it is.
| Activity | Allowance | Flat rate | Wins above |
|---|---|---|---|
| Sale of goods | 71% | 1% | 3.4% average rate |
| Commercial services (BIC) | 50% | 1.7% | 3.4% average rate |
| Liberal profession (BNC) | 34% | 2.2% | 3.3% average rate |
The tipping point depends neither on your turnover nor on your household: it is the flat rate divided by the taxable share of your turnover. That is why it lands in almost the same place in all three cases.
She collects €30,000 in 2026 as a liberal professional, and her household earns €40,000 of taxable salary.
Without the option, the 34% allowance brings her turnover down to €19,800, added to the €40,000. The household is taxed on €59,800, that is €11,044.
With the option, she pays 2.2% of €30,000, that is €660. Her €40,000 of salary is still taxed, but at the rate of the total income: €7,387 rather than €5,104.
Total with the option: €8,047 against €11,044. She saves €2,997. Without the effective rate rule, a calculator would show €5,764 and therefore a gain twice as large as the reality.
First check that your reference tax income makes you eligible. That is a separate condition.
Apply to URSSAF by 30 September at the latest, to apply from the following 1 January.
If you start during the year, you have until the last day of the third month following registration.
Keep reporting your turnover on the annual return. It is what builds your reference tax income.
Do nothing. Without any step, you stay on the scale, which is the default.
Redo the calculation each autumn. A higher-income year can reverse the result.
If you had already opted in, you give it up by 30 September at the latest, to leave on 1 January.
If your reference tax income goes back above the cap, the option ends by itself.
The result differs from most flat-rate tax calculators because they leave out the effective rate rule. Under the flat-rate option your turnover leaves the taxable base, but it is still used to set the rate applied to your other income. For a household with a salary alongside, ignoring it understates the tax by thousands of euros.
The flat-rate option is not always worth it, and that is the most common trap. If your household is not taxable you owe nothing under the scale, while the option takes its cut regardless. You then pay a flat charge on income the scale left untaxed.
In 2026, the flat-rate option starts paying off as soon as your household average tax rate goes above roughly 3.4%. The exact figure is 3.3% for liberal activities and 3.4% for services and sales. It depends neither on your turnover nor on your household: it is the ratio between the flat rate and the taxable share of your turnover.
The average rate to enter is your whole household's, not your marginal bracket. It is total tax divided by total taxable income, shown on your tax notice. Someone in the 30% bracket often has a much lower average rate.
The flat-rate option must be chosen by 30 September of the year before the one it applies to. If you start your business during the year, you have until the last day of the third month following the month of registration.
This calculation does not replace a tax notice: it compares two tax regimes using the 2026 scale and the family quotient cap, without tax reductions or credits and without special situations. It gives an order of magnitude and a direction, not a binding amount.
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