nl-tax-box2

NL Tax Box 2

Background helper for Box 2 substantial-interest preparation notes.

Use this skill only for source-backed preparation support for:

• annual_2025: annual actual Box 2 inputs from taxpayer evidence.
• provisional_2026: estimated or baseline-derived Box 2 inputs for a provisional assessment.

This helper may be called through a Skill/Task tool or inlined by an owning workflow when no such tool exists. The same output contract applies either way.

Read first

Resolve every workspace/... path against workspace_root from session-progress.yaml (or profile.yaml); never create a second workspace/ tree. _shared/ is the plugin-shared folder at this skill's ../_shared/. Read ../_shared/runtime-contract.md first. Resolve bundled files relative to this skill directory with the host's skill-resource or file tools. Do not depend on shell visibility or vendor-specific environment variables.

• reference/box2-annual-2025.md
• reference/box2-provisional-2026.md

Python is optional. Do not ask the taxpayer to install Python and do not make completion depend on it. The agent owns classification, questions, and the workpack. If an already-resolved bundled script is available, the agent may run scripts/calculate_box2_tax.py input.json as a mechanical cross-check after it has built an explicit, source-backed payload. The script validates before it calculates and records check_performed_by: checked_by_script.

Whether or not the script is run, apply this same checklist and record check_performed_by: checked_by_agent for the manual path:

1. Require explicit workflow and matching integer tax_year; never infer one from the other.
2. Require substantial_interest_pct, actual booleans for resident_full_year and standard_ab_case, and explicit source-backed values for regular_benefits, disposal_benefit, and loss_setoff.
3. Reject unknown payload fields instead of treating a misspelled amount as zero. Other amount fields may be included only when collected from evidence.
4. Stop before calculation for a non-standard residence/AB case or any complex marker listed under Never.
5. When loss_setoff is greater than zero, calculate only after a reviewer has confirmed it and the payload records loss_setoff_reviewed: true plus a non-empty loss_setoff_source; otherwise return it as a review question.
6. For a partner allocation, require an actual full_year_fiscal_partner: true boolean and percentages totaling 100%.
7. Apply the year-pinned lower bracket before the upper bracket, then apply Dutch dividend withholding tax as a credit. Treat the result as indicative.