Bonus Tax in Kenya: PAYE Rules for Employers

A bonus is taxable employment income in Kenya, and employers deduct PAYE using progressive income-tax bands rather than a separate flat bonus tax. For a current-period bonus, calculate PAYE on taxable pay including the bonus and compare it with PAYE without the bonus to explain the additional withholding. Deferred bonuses and payments earned over earlier periods need a separate lump-sum review before payroll is finalised.

Which Rules Govern Bonus PAYE?

KRA’s PAYE Brochure 2026/27 expressly lists bonuses among taxable cash employment payments. Salary, commissions, gratuity and overtime are also listed. A Christmas bonus, performance award or thirteenth-month salary is not outside PAYE simply because it has a different payroll label.

The Income Tax (Pay As You Earn) Rules, 2026, Legal Notice No. 185 dated 18 September 2026, repeal the former PAYE Rules. Under these rules, monthly pay means gross emoluments receivable during the month. That wording matters: checking only the bank-transfer date is not a sufficient review of a deferred payment.

The older KRA employer PAYE guide still appears prominently in searches. Do not use it as the controlling authority where it differs from the 2026 Rules or current KRA rates.

PAYE Bands for a Bonus Calculation

Apply the bands to taxable pay, not automatically to the gross bonus alone. Establish the applicable allowable deductions before calculating tax.

KRA states personal relief of KSh 2,400 per month, equivalent to KSh 28,800 annually. Under the 2026 Rules, monthly personal relief includes the current month’s relief and unused monthly personal relief from earlier months in the same year of income.

A bonus can push part of an employee’s taxable pay into a higher band. It does not retrospectively move all their pay into that band, and there is no rule that every bonus attracts the highest rate.

Explain the Additional PAYE, Not Just the Rate

Use this reconciliation for a current-period payment:

Additional PAYE attributable to the bonus = PAYE on taxable pay including the bonus minus PAYE on taxable pay excluding the bonus.

Both calculations should use consistent assumptions about allowable deductions and relief. If the bonus changes an applicable deduction, reflect that change in the calculation rather than treating gross bonus and additional taxable pay as interchangeable.

For an employee whose bonus crosses a band boundary, the additional taxable income is taxed across the relevant bands. This is why a single percentage quoted before payroll can misstate take-home pay.

Use the Kenya PAYE calculator to check current-period calculations. If management promises a take-home bonus, use the net-to-gross calculator as a budgeting aid, then validate the payment period and deduction treatment before approval.

Kenya PAYE calculatorWork out net pay and every deduction for any salary.

Separate Current-Period Bonuses From Earlier Earnings

Current-Period Performance Bonus

Where the payment belongs in the current month’s emoluments, bring it into that month’s PAYE calculation. If payroll pays the bonus separately from salary, reconcile both runs so the final withholding reflects the combined position.

A separate payment run is not a fresh entitlement to monthly personal relief. Track relief already used and any eligible unused relief from earlier months rather than granting relief again because another payslip has been produced.

Deferred Bonuses, Arrears and Other Lump Sums

KRA treats a one-time payment such as a bonus as a lump-sum payment from which the employer must recover the appropriate tax before releasing the balance. Do not assume that every payment labelled “bonus” can be put through an ordinary same-month calculator without further analysis.

For a deferred award, backdated commission, salary arrears or termination-related payment, assemble:

• The scheme or contract wording that explains the payment.
• The period over which the employee earned it.
• Evidence of when entitlement arose and when it became due.
• The approval and intended payment dates.
• Earlier payroll records relevant to the calculation.

Use those facts to determine the appropriate lump-sum treatment. Escalate uncertain period allocation to the payroll tax reviewer before releasing the net amount. Equally, do not spread a bonus across earlier months merely because that produces a lower withholding figure.

Test NSSF, SHIF and Housing Levy Separately

PAYE taxability does not answer every statutory deduction question. Each deduction needs its own earnings-base assessment.

NSSF: Bonuses Are Fluctuating Emoluments

The NSSF Member Contributions Regulations define fluctuating emoluments to include bonuses and commissions. Mandatory pension contributions are based on monthly pensionable earnings excluding fluctuating emoluments.

The practical control is to keep a genuine bonus out of the mandatory NSSF pensionable-earnings base. Do not configure payroll to increase NSSF automatically whenever a taxable cash payment is added. Conversely, do not relabel ordinary salary as a bonus without examining its actual character.

SHIF: Review Gross Salary or Wage

The Social Health Insurance Regulations provide for a monthly SHIF contribution of 2.75% of gross salary or wage for a household with income derived from salaried employment. That is a different basis from PAYE taxable pay and NSSF pensionable earnings.

Check the bonus against the applicable gross salary or wage treatment. Its exclusion from NSSF is not, by itself, evidence that it is excluded from SHIF. Record the classification used in payroll rather than copying the NSSF setting.

Affordable Housing Levy: Check Both Sides

KRA states an employee levy of 1.5% of gross salary and an additional matching employer contribution of 1.5%. Review whether the payment falls within the applicable gross-salary base rather than using PAYE taxability as the deciding test.

Where the payment is included in that base, capture both the employee deduction and employer contribution. An approval showing only the employee’s gross bonus will otherwise miss the employer-side levy cost.

What HR Should Approve and Retain

The Employment Act requires an itemised pay statement and a written statement of statutory deductions. Make the bonus calculation understandable to the employee and traceable to the payroll return.

Keep the following supporting records with the bonus payroll file:

• Management approval and the relevant scheme or contract clause.
• Performance evidence and the period earned.
• A clear statement of whether the award is gross or a promised net amount.
• PAYE calculations, relief reconciliation and statutory deduction classifications.
• The gross-to-net reconciliation, payslip and payment evidence.
• Reconciliation between any separate bonus run and the monthly return.

On the payslip, show the bonus distinctly from regular salary and make the deductions identifiable. For an employee query, provide the PAYE comparison with and without the bonus. Keep these controls within the employer’s payroll process, rather than handling the payment as an unexplained transfer outside payroll.

Filing and Payment Controls

KRA requires the employer to file the PAYE return through iTax and remit the tax by the ninth day of the following month. A separate bonus payment run should therefore feed into the relevant return reconciliation, not remain in an isolated spreadsheet.

Do not confuse that deadline with the Affordable Housing Levy deadline. KRA states that AHL is due by the ninth working day after the end of the month in which gross salary was due or gross income was received or accrued.

Before release, the payroll reviewer should sign off the payment period, deduction bases, relief reconciliation, net payment and employer cost. These checks address the main bonus-payroll risks: incorrect period treatment, duplicate relief and applying every deduction to the same earnings base.

Sources

Kenya Revenue Authority - PAYE Brochure 2026/27 - Taxable bonuses, monthly PAYE bands and personal relief. Kenya Law - Income Tax (Pay As You Earn) Rules, 2026 - Replacement PAYE rules, monthly pay and unused personal relief. Kenya Revenue Authority - Taxation of Lump Sum Payments - Withholding from lump sums and treatment of earlier-period earnings. Kenya Law - National Social Security Fund (Member Contributions) Regulations - Pensionable earnings and exclusion of fluctuating emoluments, including bonuses. Kenya Law - Social Health Insurance Regulations - SHIF contribution rate and gross salary or wage basis. Kenya Revenue Authority - Affordable Housing Levy Notice and iTax Guide - Employee and employer levy rates, contribution base and payment deadline.

Frequently asked questions

Is a Christmas bonus or thirteenth-month salary taxable in Kenya?+

Yes. KRA expressly includes bonuses among taxable employment cash payments, alongside salary and commissions. Calling a payment a Christmas bonus or thirteenth-month salary does not create a separate PAYE exemption.

Is the whole bonus taxed at 35%?+

No. Kenya uses progressive PAYE bands, with the 35% monthly rate applying to taxable income above KSh 800,000. A bonus can fall across several bands, depending on the employee’s other taxable pay.

Should personal relief be applied again to a separately paid bonus?+

Do not grant a duplicate monthly relief merely because the bonus is processed separately. Reconcile the bonus run with the employee’s regular payroll. Under the 2026 PAYE Rules, monthly personal relief includes the current month’s relief and unused monthly personal relief from earlier months in the same year of income.

Are bonuses subject to NSSF contributions?+

The NSSF Member Contributions Regulations classify bonuses as fluctuating emoluments. Mandatory contributions are calculated on monthly pensionable earnings excluding fluctuating emoluments, so a genuine bonus should not automatically increase the NSSF contribution base. Check the payment’s actual character rather than relying only on its payroll label.

When must an employer remit PAYE deducted from a bonus?+

KRA requires employers to file the PAYE return through iTax and remit the tax by the ninth day of the following month. Reconcile any separate bonus run into the relevant payroll return. Payments earned over earlier periods need a lump-sum treatment review before the withholding calculation is finalised.