3. United States — Federal Payroll and Year-End Forms

The United States engine performs a federal payroll preview covering FIT, FICA and FUTA, computed by the us_calc.go calculator. Its routes sit under the US payroll and US-forms paths, following the same pattern as every country engine, whose controllers live in <cc>_payroll_controller.go files and whose calculation logic lives under pkg/payroll/.

On top of the preview, the engine generates the core United States statutory outputs:

  • W-2 — the annual wage and tax statement.
  • Form 941 — the quarterly federal tax return.
  • Form 940 — the annual FUTA return.
  • Form 1099-NEC — non-employee compensation.

The presence of Form 1099-NEC reflects that the United States engine distinguishes employees from contractors. A contractor profile is stored in the payroll_config.us_contractor field as polymorphic JSONB, letting the same payroll configuration structure carry contractor-specific data without a separate rigid schema. This means an organisation can run federal employee payroll and still produce non-employee compensation reporting for its contractors from the same module.

Taken together, the engine covers the recurring federal cadence — quarterly 941 returns and the annual 940 and W-2 at year end — alongside contractor reporting, giving a United States organisation the baseline set of federal filings generated directly from its payroll data.