Understanding payroll in Tunisia: CNSS, IRPP and CSS

Producing a payslip in Tunisia means running several calculations in the right order: the social contribution, the professional expenses allowance, family allowances, progressive tax, the solidarity contribution. One mistake and you have an unhappy employee, or an exposure in front of the authorities. Here are the rates in force, the full scale, and a gross-to-net calculation set out line by line.

The three deductions in Tunisian payroll

On a Tunisian employee's payslip, three deductions turn the gross salary into net pay:

• The CNSS (Caisse nationale de sécurité sociale, the national social security fund): the social contribution, with an employee share withheld from the salary and an employer share borne by the company. It funds retirement, health insurance, family benefits and, since 2025, unemployment insurance.
• The IRPP (impôt sur le revenu des personnes physiques, personal income tax): a progressive, bracketed tax, withheld at source by the employer and paid over to the Treasury.
• The CSS (contribution sociale de solidarité, the social solidarity contribution): an additional levy based on taxable income, intended to strengthen the resources of the social security funds.

The three are calculated in that order, and the order matters: applying the IRPP before deducting the CNSS would overstate the tax, because the social contribution is deductible from the taxable base.

The CNSS contribution: employee and employer rates

The CNSS is calculated on the gross salary (base salary, bonuses, allowances and benefits linked to the job). For the general scheme of the non-agricultural private sector, the rates in force in 2026 are as follows:

Share	Rate on the gross	Who bears it
Employee share	9.68%	Withheld from the employee's salary
Employer share	17.07%	Borne by the company
Total paid to the fund	26.75%	Declared and paid over by the employer

Both rates rose by 0.5 point on each side on January 1^st, 2025 (2025 Finance Act, Act No. 2024-48 of 9 December 2024): they were previously 9.18% and 16.57%. The extra point funds the new unemployment insurance scheme covering redundancy on economic grounds, split equally between employee and employer.

Two useful clarifications. First, the work-accident and occupational-illness contribution is borne solely by the employer and varies by sector of activity: the employer rate actually notified by the fund may therefore differ from the standard rate. Second, these percentages apply to the general non-agricultural scheme: the agricultural sector, the special schemes and wholly exporting companies come under separate scales.

The IRPP: from taxable salary to tax

Income tax does not apply to the gross, but to a net taxable income obtained after three successive subtractions.

1. The taxable salary

This is the gross less the employee CNSS contribution: taxable salary = gross − 9.68%. The social contribution is fully deductible.

2. The professional expenses allowance

Employees benefit from a flat-rate deduction of 10% of the taxable salary, capped at 2,000 DT per year (about 166.667 DT a month). The cap is reached as soon as the taxable salary exceeds 20,000 DT a year: beyond that, the deduction stays fixed at 2,000 DT, which speeds up the progression of tax on higher salaries.

3. Deductions for family allowances

Then come the allowances linked to personal circumstances, expressed as annual amounts:

• Head of household: 300 DT a year.
• Dependent child: 100 DT per child, limited to the first four children (under 20 on January 1^st of the tax year).
• Child in higher education without a grant (under 25): 1,000 DT.
• Disabled child: an increased deduction applies whatever the child's age or rank. Its amount has been raised several times — check the value in force with the Directorate General of Taxation before configuring your payroll.
• Dependent parents: a deduction also exists, subject to income conditions.

The bracketed scale

The 2025 Finance Act (Article 36 of Act No. 2024-48 of 9 December 2024) overhauled the scale, taking it from 5 to 8 brackets, with the top marginal rate raised to 40%. It applies to income earned since January 1^st, 2025 and remains the reference for 2026 payroll:

Annual net taxable income	Rate for the bracket
Up to 5,000 DT	0%
From 5,000.001 to 10,000 DT	15%
From 10,000.001 to 20,000 DT	25%
From 20,000.001 to 30,000 DT	30%
From 30,000.001 to 40,000 DT	33%
From 40,000.001 to 50,000 DT	36%
From 50,000.001 to 70,000 DT	38%
Above 70,000 DT	40%

The scale is progressive: each rate applies only to the portion of income falling within its bracket. An employee whose net taxable income reaches 25,000 DT does not pay 30% on the whole amount: they pay 0% on the first 5,000 dinars, 15% on the next 5,000, 25% on the following 10,000, and 30% only on the last 5,000. That is why a pay rise never reduces net pay: only the additional portion is taxed at the higher rate.

Since the scale is annual, monthly payroll works by annualisation: the taxable income is projected over twelve months, the annual tax is calculated, then divided by twelve to give the month's withholding.

The CSS: the social solidarity contribution

The social solidarity contribution is added to the IRPP and is calculated on the same base: annual net taxable income. Its standard rate is 1%, but it was brought down to 0.5% for 2026 by the 2026 Finance Act (Article 87 of Act No. 2025-17 of 12 December 2025). This reduction is presented as a temporary measure, limited to 2026: unless it is extended, the 1% rate applies again thereafter.

Employees whose annual net income does not exceed 5,000 DT after deductions — that is, those falling in the 0% bracket — are exempt.

The full calculation, step by step

Take an example: an employee in the non-agricultural private sector, head of household with two dependent children, paid 2,000.000 DT gross per month. Here is the sequence, rounded to the millime.

Step	Calculation	Amount
Monthly gross salary	—	2,000.000 DT
− Employee CNSS	2,000.000 × 9.68%	− 193.600 DT
= Monthly taxable salary	2,000.000 − 193.600	1,806.400 DT
Annual taxable salary	1,806.400 × 12	21,676.800 DT
− Professional expenses	10% = 2,167.680 → capped	− 2,000.000 DT
− Family allowances	300 + (2 × 100)	− 500.000 DT
= Annual net taxable income	21,676.800 − 2,500.000	19,176.800 DT
IRPP bracket 0 → 5,000	0%	0.000 DT
IRPP bracket 5,000 → 10,000	15% × 5,000.000	750.000 DT
IRPP bracket 10,000 → 19,176.800	25% × 9,176.800	2,294.200 DT
= Annual IRPP	750.000 + 2,294.200	3,044.200 DT
− Monthly IRPP	3,044.200 ÷ 12	− 253.683 DT
− Monthly CSS	(0.5% × 19,176.800) ÷ 12	− 7.990 DT
= Net salary payable	2,000.000 − 193.600 − 253.683 − 7.990	1,544.727 DT

The employee therefore receives about 77% of their gross salary. The 455.273 DT difference splits between the social contribution (193.600 DT), tax (253.683 DT) and the solidarity contribution (7.990 DT).

What does an employee really cost?

The gross is not the cost of employment. On top of it the company bears the employer share of the CNSS, along with other contributions based on payroll costs, such as the vocational training tax and the contribution to the housing promotion fund for employees. Taking the same employee:

Item	Calculation	Monthly amount
Gross salary	—	2,000.000 DT
+ Employer CNSS	2,000.000 × 17.07%	+ 341.400 DT
= Employer cost	2,000.000 + 341.400	2,341.400 DT
Net received by the employee	see previous table	1,544.727 DT
Gap between employer cost and net	2,341.400 − 1,544.727	796.673 DT

In other words, for 100 DT paid to the employee, the company spends about 152 DT, excluding the work-accident contribution and sector-specific levies on payroll costs. It is that figure — and not the gross — that you should use to budget a hire, price a project or build an hourly cost price.

Two reference points for framing pay: the 2026 SMIG stands at 554.736 DT per month for the 48-hour week (2.667 DT an hour) and at 470.251 DT for the 40-hour week (2.713 DT an hour), under Decree No. 2026-67 published in JORT No. 44 of 30 April 2026.

Declarations: the employer's obligations

Calculating payslips is only part of the job. Every month and every year, the employer must also:

1. Produce and hand over a detailed payslip to each employee, showing the gross, every deduction and the net payable.
2. Declare and pay over the CNSS contributions. The declaration is in principle quarterly (monthly for some employers) and is filed online on the fund's portal. Any delay exposes you to penalties: keep to the timetable notified by the CNSS.
3. Pay over the IRPP and CSS withheld at source during the month following the deduction, within the deadline set by the tax calendar, which differs depending on whether the employer is an individual or a company.
4. File the employer's annual declaration, summarising the salaries paid and the deductions made over the year, within the deadline set by the Directorate General of Taxation.
5. Track leave, balances, bonuses and advances, which feed into the following month's calculation.
6. Manage contracts, their end dates and their renewals.

Done by hand, these tasks take up several days a month and concentrate most of the risk of error.

The most frequent payroll mistakes in SMEs

Handling payroll files day in, day out, the same mistakes keep coming back. The five most costly:

• Working with out-of-date rates. The move from 9.18% to 9.68% in 2025 and the CSS at 0.5% in 2026 caught out many spreadsheets that were never updated. The result: twelve incorrect payslips to put right.
• Forgetting the cap on professional expenses. Applying 10% without capping at 2,000 DT understates the tax on every salary above 20,000 DT taxable a year — and the gap widens the higher the salary.
• Adding the increased deduction for a child in higher education or with a disability to the deduction for that child's rank, instead of substituting it.
• Calculating the IRPP on a monthly basis without annualising, or changing the base mid-year when a bonus is paid, which produces withholdings that are inconsistent from one month to the next.
• Confusing gross with employer cost when budgeting a hire, then discovering a 17% overrun on the forecast payroll costs.

How payroll software avoids these mistakes

A payroll engine applies the calculation sequence always in the same order, on every payslip, with no missed cap and no rounding error. Swifto's HR & Payroll module chains the CNSS withholding, the professional expenses allowance and its cap, the deductions for family allowances — including the substitution for children in higher education or with a disability — then the bracketed IRPP scale and the CSS, and issues the corresponding payslip.

Since the scale and the rates are configurable, a change in the finance act is reflected in a single entry rather than a manual rewrite of every formula. The software also handles leave and its balances, contracts, bonuses and advances, as well as producing the social declarations — all elements that feed the payslip and whose accuracy determines that of the calculation.

Because everything is integrated into the ERP, payroll costs feed directly into cash flow and accounting: the real employer cost appears in the forecast with no re-keying. To understand the overall logic, read what an ERP is and why your SME needs one, or find out how to digitalize payroll and HR beyond the payslip.

Frequently asked questions

This article is for information purposes and does not replace personalised employment or tax advice. The rates, thresholds and scales in force are set by the regulations and the finance act; check them with your accountant.