- France uses a sliding scale — five bands from 0% to 45% — similar in principle to the UK's basic, higher, and additional rate system, but applied very differently
- Your rate only ever applies to the portion of income in that band, never to everything below it — the same principle as the UK, but with different thresholds
- Your tax is calculated on your household's combined income divided by shares, not on your individual income — which can significantly lower your effective rate
- The 10% pension abattement was threatened in the 2026 budget but retained — pension income still gets the allowance before entering the bands
The single most common misunderstanding of the French tax system — shared by French and expat filers alike — is assuming that your tax bracket is the rate applied to all your income. It isn't.
France uses what it calls a barème progressif — a sliding scale of tax bands, where each band has its own rate, and only the income that falls into a given band gets taxed at that band's rate. If you're used to the UK system, this is the same principle as basic rate (20%), higher rate (40%), and additional rate (45%) — a UK higher rate taxpayer doesn't pay 40% on every pound they earn, only on the slice above the basic rate threshold. France works the same way, just with different band thresholds and the added complication that everything is calculated per household share rather than per individual.
For the broader picture of how income tax sits alongside social charges as France's two separate charges, see how the French tax system works. This article is specifically about how the income tax bands function, and what that means for UK expats declaring worldwide income.
The 2026 bands
These are the bands that apply to income received in 2025 and declared in 2026:
| Band | Rate | Applies per share per year |
|---|---|---|
| Band 1 | 0% | Up to €11,600 |
| Band 2 | 11% | €11,601 to €29,579 |
| Band 3 | 30% | €29,580 to €84,577 |
| Band 4 | 41% | €84,578 to €181,917 |
| Band 5 | 45% | Above €181,917 |
These figures are per share — not per person, not per household total. That distinction is what makes the system work the way it does, and it's explained in the section below.
Why "being in the 30% bracket" doesn't mean 30% on everything
The bands are applied like layers — each one only catches the income that falls into its range, and everything below the threshold of each band is taxed at the lower rate beneath it. No income is ever retrospectively taxed at a higher rate because your total crossed a threshold.
A concrete example: a single person (1 share) with taxable income of €40,000:
| Band | Income in this band | Rate | Tax |
|---|---|---|---|
| 0% band | €11,600 | 0% | €0 |
| 11% band | €17,979 (€29,579 − €11,600) | 11% | €1,978 |
| 30% band | €10,421 (€40,000 − €29,579) | 30% | €3,126 |
| Total | €40,000 | €5,104 |
Their marginal rate is 30% — that's the band their highest euro of income sits in. Their effective rate (tax owed divided by total income) is 12.8%. The 30% rate only applied to the €10,421 above the 11%/30% threshold — not to the entire €40,000.
This is why the bracket you're in matters much less than people assume. Being in the 30% band doesn't mean you're paying 30% on your income. It means the euros above €29,315 are paying 30%, and everything below is paying less.
The share system: why household structure changes everything
Bands are applied to income per share, not to your household total directly. The quotient familial divides your household's combined taxable income by the number of shares assigned to it, runs the band calculation on that per-share figure, then multiplies the result back up.
The practical effect: a couple with combined income of €60,000 (2 shares) has a per-share income of €30,000 — not €60,000. They enter the 30% band by only €421 per share, compared to a single person on €60,000 entering by €30,421. The couple owes substantially less income tax on the same total income.
This is why household composition is the first thing to establish before doing any income tax calculation — the number of shares fundamentally alters which rate applies to what.
What counts as taxable income for UK expats
Before the bands are applied, several things are deducted or adjusted:
The 10% pension abattement. Pension income — including UK pensions declared on the French return — gets a 10% flat allowance deducted before entering the income tax bands. So €30,000 of UK pension income becomes €27,000 for income tax purposes. This allowance was under threat during the 2026 budget process but was ultimately retained unchanged, which is relevant reassurance if you'd heard rumours of it being scrapped.
The CSG déductible. If you pay social charges on investment or pension income (and don't hold an S1 covering you fully), a portion of those social charges — the deductible fraction of the CSG — reduces your taxable income the following year. The mechanics of this are covered in the total tax bill worked example.
Treaty exemptions. Some income types are taxed exclusively in the source country under the France-UK treaty — most notably UK government service pensions — and don't enter the French income tax bands at all, even though they must still be declared. See the government service pension guide for how this works in practice.
The worldwide income point. As a French tax resident, all of your income — UK pensions, UK rental, UK dividends, everything — goes into the household pot for the band calculation. You can't exclude your UK income because it feels like "UK income." What the treaty does is determine whether France gets to keep the resulting tax, or whether a credit mechanism offsets it. The declaration obligation, and the band calculation, applies to the full worldwide picture first. See how the France-UK double tax treaty works for that credit mechanism explained.
Marginal rate vs effective rate: the number that actually matters
Your marginal rate is the rate on your highest band — it's used for planning decisions (does it make sense to put more into a PER pension deduction? At what rate does my next pound of income get taxed?). It's a useful number, but it's not what you actually pay.
Your effective rate is your total income tax bill divided by your total income. For most UK expats on pension income sitting in the lower bands, the effective rate is considerably lower than the marginal rate, because most of the income is taxed at 0% and 11% — not at the marginal band rate.
A couple with €50,000 combined pension income (2 shares, no other income):
| Step | Calculation | Amount |
|---|---|---|
| 10% pension allowance | €50,000 × 90% | €45,000 taxable |
| Per share | €45,000 ÷ 2 | €22,500 per share |
| 0% band | €11,600 | €0 |
| 11% band | €10,900 (€22,500 − €11,600) | €1,199 per share |
| × 2 shares | €2,398 total | |
| Effective rate | €2,398 ÷ €50,000 | 4.8% |
Their marginal rate is 11%. Their effective rate is 4.8%. Both statements are true, and both are useful in different contexts — but neither one alone tells the full story.
For a full picture combining income tax with social charges into one household total, see the total tax bill worked example — it shows how these two calculations add up across several realistic UK expat profiles.
You can also use Taxpert's French Tax Bill Estimator to run these numbers for your own household figures — pension income, S1 status, and investment income all included.
The contribution différentielle: only relevant at very high incomes
A measure introduced in 2025 and retained for 2026 — the contribution différentielle sur les hauts revenus — sets a floor of 20% effective income tax for households with very high reference income. This is not relevant for the vast majority of UK expats in France and doesn't affect the band calculation described above. It's mentioned here purely so you're not confused if you encounter references to it elsewhere.
Frequently Asked Questions
Does the UK-France double tax treaty change which bands apply?
No — the treaty doesn't change the bands themselves. What it does is determine whether France gets to actually keep the income tax calculated under those bands, or whether a credit is given for tax paid in the UK on the same income. The bands apply to your full worldwide income regardless; the treaty operates as a relief mechanism on top of that calculation.
If my income pushes me into the 30% band, does all my income get taxed at 30%?
No. Only the income above €29,579 per share is taxed at 30%. Everything below that threshold is taxed at the lower rates — 0% up to €11,600 and 11% from €11,600 to €29,579. Moving into a higher band never increases the rate on income already taxed at a lower band.
Is the 10% pension abattement still available in 2026?
Yes. It was threatened during the 2026 budget process but ultimately retained. Pension income — including UK pensions — still gets a 10% allowance deducted before the income tax bands are applied.
How does the quotient familial change the effective rate?
By reducing the per-share income, it keeps more of the combined household income in lower bands. A couple's combined income is divided by 2 before the bands are applied, then the result is multiplied back up — meaning both partners effectively benefit from the lower bands on their proportionate share of the total. See the quotient familial guide for full details.
Can I work out my marginal rate without doing the full calculation?
Roughly, yes — divide your household's taxable income by your number of shares and see which band the result sits in. That's your marginal rate for the income tax portion (not including social charges). Remember the pension allowance reduces pension income by 10% before this step.