Short answer
For a salaried employee under the general Algerian regime, CNAS states a global rate of 34.5%:
- 25% of the contribution base paid by the employer;
- 9% of the contribution base withheld from the employee;
- 0.5% of gross payroll for social works.
In payroll, these are three different amounts. Mixing them together can distort the employee net pay or the employer cost.
Example on 80,000 DZD
If the CNAS contribution base is 80,000 DZD, the calculation is:
| Item | Calculation | Amount |
|---|---|---|
| Employee CNAS deduction | 80,000 x 9% | 7,200 DZD |
| Employer CNAS share | 80,000 x 25% | 20,000 DZD |
| Social works | 80,000 x 0.5% | 400 DZD |
| Payroll-related total | 7,200 + 20,000 + 400 | 27,600 DZD |
The employee mainly sees the 7,200 DZD deduction on the payslip. The company must also track the full employer cost: gross pay, employer share, social works, salary IRG and net pay.
Which base should be used?
The CNAS base is the salary subject to social contributions. It starts from salary and work-related pay items, then excludes specific elements mentioned by CNAS, such as family benefits, expense reimbursements and certain exceptional indemnities.
The monthly salary subject to contribution cannot be lower than the current SNMG. As of today, the SNMG is 20,000 DZD. This is a contribution-base rule; it should not be confused with every possible net pay situation after legal deductions or payroll adjustments.
Formula
Employee deduction = CNAS base x 9%
Employer share = CNAS base x 25%
Social works = gross payroll x 0.5%The result should then be reconciled with salary IRG, the payslip, social contributions and the accounting entry.
Declaration and payment
According to CNAS, declaration and payment depend on workforce size:
| Workforce | Practical periodicity |
|---|---|
| Fewer than 10 employees | Quarterly declaration |
| 10 employees or more | Monthly declaration |
Even when the company declares quarterly, payroll should still be reviewed every month. Waiting until quarter-end makes errors harder to explain.
CNAS or CASNOS?
This method applies to salaried workers affiliated with CNAS. Independent and non-salaried workers fall under CASNOS, where the contribution logic is different. Do not apply a salaried CNAS payslip calculation mechanically to a trader, partner or independent professional.
Common mistakes
- Using “CNSS” when the salaried-worker body in Algeria is CNAS.
- Applying 34.5% as if it were one employee deduction.
- Failing to separate employee share, employer share and social works.
- Classifying a bonus without deciding whether it enters the CNAS base and the IRG base.
- Comparing CNAS declarations with accounting without reviewing the general ledger.
Official sources
FAQ
Is CNAS calculated on net pay or gross pay?
It is calculated on the contribution base, determined from salary items subject to social contributions. It is not calculated on net pay.
Is the employee rate 9% or 34.5%?
The employee deduction is 9%. CNAS gives a 34.5% global rate because it also includes the employer share and social works.
Does CNAS replace salary IRG?
No. CNAS is a social contribution. Salary IRG is a tax withholding. They must be shown separately in payroll and accounting.
Takeaway
A reliable CNAS calculation is not only a multiplication. It must explain the base, separate the shares, produce a readable payslip, prepare the declaration and leave an accounting trail.