Source: https://guthlabs.ai/docs/instruments/payroll-deduction-paystub-breakdown-simulator/implementation/

instrument implementation / implementation-contract

# Payroll Deduction / Paystub Breakdown Simulator implementation

A source-bound implementation contract for Payroll Deduction / Paystub Breakdown Simulator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t7-129

**Effect**: Computation or source lookup only

## Input and validation requirements

The zero-gross boundary produces an undefined retained-percentage calculation, and an invalid state code produces an undefined lookup and therefore undefined net pay. The branch fixture also exposes a discontinuity at its lookup-table switch, while retirement-sign interpretation materially changes the result.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "gross_annual": 50000,
    "filing_status": "single",
    "state": "TX",
    "pre_tax_benefits_annual": 1200,
    "retirement_percent": 0.06
  },
  "expected_outputs": {
    "federal_tax_annual": 3512,
    "state_tax_annual": 0,
    "social_security_annual": 3025.6,
    "medicare_annual": 707.6,
    "benefits_annual": 1200,
    "retirement_contribution_annual": 3000,
    "net_annual": 38554.8,
    "percent_of_gross_retained": 77.1096
  },
  "reference_data": {
    "federal_2024_single_standard_deduction": 14600,
    "federal_2024_single_brackets": [
      {
        "up_to": 11600,
        "rate": 0.1
      },
      {
        "up_to": 47150,
        "rate": 0.12
      }
    ],
    "social_security_rate": 0.062,
    "medicare_rate": 0.0145,
    "social_security_2024_wage_base": 168600,
    "texas_individual_income_tax_rate": 0,
    "source_convention": "IRS 2024 tax-year brackets and standard deduction; IRS/SSA 2024 FICA rates and wage base; Texas Comptroller widely tabulated no-individual-income-tax convention"
  },
  "working": "Retirement = 50,000 x 0.06 = 3,000. Federal taxable income = 50,000 - 1,200 - 3,000 - 14,600 = 31,200. Federal tax = (11,600 x 0.10) + ((31,200 - 11,600) x 0.12) = 1,160 + 2,352 = 3,512. FICA wage base = 50,000 - 1,200 = 48,800. Social Security = 48,800 x 0.062 = 3,025.60. Medicare = 48,800 x 0.0145 = 707.60. Texas tax = 50,000 x 0 = 0. Net = 50,000 - 3,512 - 0 - 3,025.60 - 707.60 - 1,200 - 3,000 = 38,554.80. Retained percentage = 38,554.80 / 50,000 x 100 = 77.1096%."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/payroll-deduction-paystub-breakdown-simulator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/payroll-deduction-paystub-breakdown-simulator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/payroll-deduction-paystub-breakdown-simulator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche7/tranche7-results.json`