adamriofc PPh 21 Circular Gross-Up & Natura Tax Optimization
Calculates circular payroll tax allowances (Gross-Up) down to Rp 1 precision using iterative mathematical bisection, integrating PMK 66/2023 Benefit-in-Kind (Natura/Kenikmatan) taxability rules and PP 58/2023 TER tables.
Circular Gross-Up & PMK 66/2023 Framework
- Mathematical Bisection Loop:
- Solves $\text{Tax Allowance} = \text{PPh 21}(\text{Base Salary} + \text{Allowances} + \text{Taxable Natura} + \text{Tax Allowance})$ iteratively.
- Ensures employee Take-Home-Pay remains 100% untouched while employer deducts the tax allowance under UU PPh Pasal 6.
- Natura / Benefit-in-Kind Thresholds (PMK 66/2023):
- Food & beverage provided to all employees: 100% tax-exempt.
- Standard housing & vehicle facilities: Exempt up to monthly statutory thresholds (e.g. Rp 2,000,000 exemption cap).
- Excess Natura above exemption threshold is added to the monthly PPh 21 taxable gross base.
Hybrid Execution Model
Pass parameters to engines/pph21-grossup-calculator.js:
calculatePPh21GrossUp({ baseSalary, regularAllowances, ptkpStatus, taxpayerIdentity, dateStr, naturaAmount, naturaExemptThreshold })
Worked Example
Input: Base salary Rp 15.000.000, PTKP TK/0, Natura amount Rp 3.000.000 (exemption Rp 2.000.000).
- Taxable Natura =
Rp 3.000.000 - Rp 2.000.000= Rp 1.000.000. - Base Taxable Cash =
Rp 15.000.000 + Rp 1.000.000= Rp 16.000.000. - Iterative Gross-Up Engine Output: Converges at
grossUpTaxAllowance= Rp 1.204.301. - Employee Net Take-Home-Pay = Rp 15.000.000 (100% protected).