TRIMF in Senegal: scale, parts and the spouse rule

The TRIMF takes up one line on a payslip and a few hundred francs. That is precisely why it is so often wrong: nobody checks it, and a gap of 1,000 FCFA a month triggers no alarm.

Yet it is one of the rare deductions where the error is structural rather than arithmetic. People do not get the division wrong — they get the number of parts wrong, by applying the employee's tax position in the income tax sense. The two notions share the same word, "parts", and do not follow the same rule.

This guide gives the scale, the rule for parts, and the distinction most sources online leave out: the effect of the spouse's income.

What is the TRIMF?

The Taxe Représentative de l'Impôt du Minimum Fiscal is a tax withheld from salary and paid over to the Direction générale des impôts et des domaines, alongside income tax. It follows the tax route, not the IPRES or CSS route.

Its logic sets it apart from everything else on the payslip: it is not proportional. There is no TRIMF rate. The scale assigns a flat amount to each band of income, and that amount is owed per person. Two employees earning 300,000 and 600,000 FCFA can pay exactly the same TRIMF, because they fall in the same band.

It is a poll tax rather than an income tax — hence its name, and hence the rule on parts that follows.

The TRIMF scale

The amounts in the scale are annual and per part. The figure to compare against the scale is the annual taxable gross, that is, the month's taxable gross multiplied by twelve.

Annual taxable gross	Annual amount per part	Per month, per part
Under 600,000 FCFA	900 FCFA	75 FCFA
600,000 to under 1,000,000 FCFA	3,600 FCFA	300 FCFA
1,000,000 to under 2,000,000 FCFA	4,800 FCFA	400 FCFA
2,000,000 to under 7,000,000 FCFA	12,000 FCFA	1,000 FCFA
7,000,000 to under 12,000,000 FCFA	18,000 FCFA	1,500 FCFA
12,000,000 FCFA and above	36,000 FCFA	3,000 FCFA

The monthly calculation fits in one formula:

Monthly TRIMF = (annual amount for the band ÷ 12) × number of TRIMF parts

One consequence of the band structure is worth knowing, because it surprises people the first time they check it: between two thresholds the amount does not move at all; crossing a threshold, it jumps. A taxable gross of 83,333 FCFA a month is 999,996 FCFA a year and gives 300 FCFA per part. At 83,334 FCFA, the annual base reaches 1,000,008 FCFA, tips into the next band, and the amount becomes 400 FCFA. One franc of monthly increase costs a hundred francs of TRIMF per month, per part.

This is not a calculation quirk, it is the scale. But it explains why a small pay rise can move a line nobody expected.

The base: taxable gross, and nothing else

The TRIMF is calculated on taxable gross — the same base as income tax. Two points decide the outcome:

• Exempt allowances are excluded. Transport allowance, mileage allowances and other exempt expense reimbursements are not part of taxable gross.
• Employee contributions are not deducted from it. This is the point most often wrong elsewhere. In Senegal, IPRES and other employee withholdings do not reduce taxable gross. So you start neither from net pay, nor from gross less contributions.

A base built on gross after contributions costs many employees a whole band, and the error repeats twelve times before it has any chance of being spotted.

TRIMF parts: one or two, never more

This is where it is decided. The rule is short:

Employee's situation	TRIMF parts
Married, spouse without income	2
Married, spouse with income	1
Single, divorced, widowed	1

The logic follows from the nature of the tax. The TRIMF is owed per person. A married employee whose spouse has no income settles it for two: their own and their spouse's. As soon as the spouse has an income of their own, they settle theirs separately, and the employee drops back to one part — exactly like a single employee.

The number of TRIMF parts never exceeds two.

There is a third case, apart from these: exemption, which corresponds to zero parts. It cannot be inferred from any family situation and must be entered explicitly on the employee record. An exempt employee keeps a TRIMF line on the payslip, at zero: the withholding is nil, but it stays visible and traceable.

TRIMF parts and tax parts: not the same thing

Both are derived from the same employee record and obey different rules. Income tax parts take dependent children into account and go up to five. TRIMF parts ignore children and cap at two.

Situation	Tax parts (income tax)	TRIMF parts
Single, no children	1	1
Single, 2 children	2	1
Married, spouse without income, no children	2	2
Married, spouse employed, no children	1.5	1
Married, spouse without income, 3 children	3.5	2
Widowed with 1 child	2	1

Read the "Single, 2 children" line: two parts for income tax, one for the TRIMF. A tool that reuses tax parts for the TRIMF doubles that employee's withholding. And the "Married, spouse employed" line produces the opposite error, more widespread still: many payroll setups apply two parts to every married employee, without asking whether the spouse has an income.

Three worked calculations

Same salary, three family situations. Monthly taxable gross: 260,000 FCFA. Annual base: 260,000 × 12 = 3,120,000 FCFA, which falls in the 2,000,000 to 7,000,000 band, at 12,000 FCFA a year per part, or 1,000 FCFA a month per part.

Single employee — 1 part 1,000 × 1 = 1,000 FCFA a month

Married employee, spouse without income — 2 parts 1,000 × 2 = 2,000 FCFA a month

Married employee, spouse employed — 1 part 1,000 × 1 = 1,000 FCFA a month

The gap between the second and third cases is 1,000 FCFA a month, or 12,000 FCFA over the year, for two married employees on the same salary. That is the whole point of the question asked at hiring: does your spouse have an income?

A fourth case, for an executive: monthly taxable gross of 875,594 FCFA, married, spouse without income. Annual base 10,507,128 FCFA, the 7,000,000 to 12,000,000 band, so 18,000 FCFA a year per part. 18,000 ÷ 12 = 1,500 FCFA, × 2 parts = 3,000 FCFA a month.

What the TRIMF does not do

Three misconceptions are worth clearing up, because they produce inaccurate payslips and annual returns.

It is not adjusted in December. Income tax is recalculated at year end on income actually received, and the difference against the monthly instalments is settled on the December payslip. The TRIMF does not work that way: it is a band amount fixed month by month, on that month's taxable gross. There is nothing to catch up.

It is not deductible. It reduces neither taxable gross nor the income tax base.

It does not belong in the income tax cumulative. On a payslip, the "income tax" year-to-date figure must carry income tax alone. Rolling the TRIMF into it inflates a number that the employee and the tax authority both read as income tax, and the discrepancy carries through to the annual statement of salaries.

What Izi Paie changes

The TRIMF is a textbook case of silent misconfiguration: the rule is simple, the error is invisible, and it repeats every month.

• TRIMF parts are derived from the family situation, spouse's income included. You record the marital status and whether the spouse has an income; the parts follow, and the employee record flags any divergence from a manually entered value rather than changing it silently.
• Tax parts and TRIMF parts are calculated separately, each under its own rule. Children count for one, not for the other.
• The scale is the one in the current tax code, applied to annual taxable gross, with band changes handled automatically — including the threshold effect a pay rise can trigger.
• A change of situation applies from the next payroll. A spouse who finds a job moves the employee from two parts to one, with no intervention.
• Exemption stays an explicit choice, never inferred, and the line shows at zero on the payslip so it remains traceable.
• The TRIMF is tracked in its own cumulative, separate from income tax. What you report at year end matches what you withheld.

The simplest way to see it is on a real case: enter a salary and a family situation in the net salary calculator, change the answer to the spouse question, and watch the TRIMF line move.

Going further: net salary calculation in Senegal walks through the full path from gross to net, and the guide to IPRES, CSS and annual declarations explains where these cumulative figures are expected at year end.