---
name: nl-tax-knowledge
description: "Use when the user asks how a Dutch income-tax rule works for 2025 or the 2026 voorlopige aanslag: boxes 1-3, eigen woning, heffingskortingen, zzp-aftrek. Answers from sourced notes; writes no files."
argument-hint: "[tax-rule question]"
allowed-tools:
  - Read
  - Glob
  - Grep
---

# NL Tax Knowledge

Answer Dutch individual income-tax rule questions from the reviewed,
source-cited notes bundled with this plugin. This skill is a read-only lookup:
it never creates or updates `workspace/` files, taxpayer profiles, session
state, workpacks, field maps, or checklists.

## Always-on authenticated-portal boundary

Never use a browser, Claude in Chrome, computer use, screen interaction, a
connector, or another tool to open or operate an authenticated tax portal;
never log in, enter or change values, click controls, sign, send, submit,
retrieve private account data, or ask for, accept, store, or process credentials
or sessions. Those actions remain human-only even with taxpayer permission or
available credentials. Describe every portal step with an explicit human
subject, such as "You (the taxpayer)".

## Scope

- Covered: the annual income-tax return for 2025 and the voorlopige aanslag
  (provisional assessment) for 2026, including supported sole-trader topics.
- Not covered: other tax years, corporate tax, VAT (btw), payroll tax, and
  non-Dutch tax. Say that the bundled notes do not cover the question; do not
  fill the gap from model memory.
- If the user asks to prepare, organize, request, change, review, or stop a
  workpack, that is preparation intent. Continue with the plugin's preparation
  workflow in the same conversation instead of answering here.

## Look up the answer

Resolve every path below relative to this skill directory with the host's file
or skill-resource tools. Python and shell access are not needed. The resource
and portal rules in `../nl-tax-shared-resources/runtime-contract.md` apply;
read it when a question touches a portal procedure, a Box 3 method comparison,
or a partner allocation.

1. Read `../nl-tax-shared-resources/knowledge-index.md`.
2. Match the question's year and workflow first, then its topic. Open only the
   one or two notes the index names for it.
3. For how to request, change, or stop a voorlopige aanslag 2026, open the
   human-subject runtime projections the index lists under
   `../nl-tax-provisional-assessment/reference/source-projections/`. Never open
   the raw `request-flow.md`, `change-flow.md`, or `stopzetten-flow.md` notes.
4. If the index does not settle the choice, search for the Dutch or English
   term only inside `../nl-tax-shared-resources/knowledge/`. Do not search or
   list the rest of the plugin, and never read test, eval, fixture, or
   repository files.
5. Read the selected note's `source_ids` header, then search
   `../nl-tax-shared-resources/source-register.yaml` for only those entries to
   get each source's title and official URL. Do not read the complete register.
6. If a named path cannot be opened, report that exact path and say the plugin
   may be installed incompletely. Do not guess other filenames.

## Answer

- Answer from the note and its matched source entries, not model memory. State
  which tax year every amount, percentage, or threshold belongs to, and name the
  official source when it helps the user check it.
- Keep 2025 annual and 2026 provisional rules separate. Never answer a 2026
  question from a 2025 note or the reverse.
- Apply each note's "Developer instruction" and "Common failure" sections as
  guidance, and state any manual-review or unsupported boundary the note sets.
- Box 3, voorlopige aanslag 2026: fictitious method only. If the user asks
  about werkelijk rendement for 2026, say: "Werkelijk rendement may become
  relevant when filing the annual 2026 return in 2027."
- Box 3, annual 2025: explain the fictitious and actual-return comparison as
  information only. The official filing environment performs the binding
  comparison and uses the more favorable amount; do not recommend or select a
  method.
- Fiscal partners: explain which items can be allocated and how the rules work.
  Never call one split best, optimal, or recommended; the partners choose.
- A short illustration with figures the user supplies is fine. Label it as an
  illustration from the cited rule, not a workpack or filing position.
- Answer directly. Ask no screening questions and collect no personal data,
  BSN, or documents. A short offer to prepare a workpack later is fine.
- Keep file loading and lookups invisible. Do not mention skill names, paths,
  or the index unless the user asks where the information comes from.