bd-income-tax-skills

License: MIT Agent Skill Built with Claude

Agent Skill for Bangladesh individual (personal) income tax. It lets any compatible AI agent (Claude, Codex, Gemini CLI, etc.) accurately answer Bangladesh personal income-tax questions and compute tax for a given assessment year — slabs, tax-free thresholds, salary exemption, the Section 78 investment rebate, minimum tax, net-wealth surcharge, TDS credit, filing/PSR rules, Tax Day, and penalties.

The skill lives in skills/bd-income-tax/. Authored to the open Agent Skills standard, so the same SKILL.md runs unmodified across the tools that adopted it.

What it does

  • Year-aware. Bangladesh income year is 1 Jul – 30 Jun → the following assessment year. Primary year AY 2026-27; also AY 2025-26 (late/prior returns) and AY 2027-28 (next year, legislated to mirror 2026-27 — for "what will I owe after my increment"). Every answer states the assessment year and governing law.
  • Gratuity & credits. Models the gratuity exemption (up to BDT 2.5 crore from an approved fund) and treats vehicle advance tax (Section 153) as a non-refundable credit, distinct from refundable salary TDS — so "a car reduces my tax" is answered correctly.
  • Deterministic math. All arithmetic runs through skills/bd-income-tax/scripts/tax_calc.py — standard library only, no network calls, no model arithmetic.
  • Sourced. Every rate/threshold is tagged with its source in references/sources.md.

Assessment-year caveat

The FY 2026-27 measures are now the Finance Act 2026 (Finance Bill passed by Parliament, effective 1 Jul 2026). On passage, the general tax-free threshold was raised from the proposed Tk 375,000 to Tk 400,000 for FY2026-27 and FY2027-28 — the calculator uses 400,000. A few edge-case figures (DPS cap, agriculture deemed-cost %, solely-agricultural exemption, delay-interest rate) remain ⚠️ unverified in the references and are deliberately not used by the calculator; confirm them against the official gazette.

Quick start (calculator)

python3 skills/bd-income-tax/scripts/tax_calc.py --selftest        # runs the canonical test cases
python3 skills/bd-income-tax/scripts/tax_calc.py --year 2026-27 --category general --salary 800000

Canonical results the self-test asserts: 13,333 / 65,070 / 7,500 / 49,500.

Install

  • skills.sh (any agent — Claude, Codex, Cursor, …): 
    npx skills add arifulislamat/bd-income-tax-skills
  • Claude Code plugin marketplace: 
    /plugin marketplace add arifulislamat/bd-income-tax-skills
/plugin install bd-income-tax@bd-income-tax-skills
  • Claude.ai / desktop apps: download bd-income-tax.zip from the latest release and upload it under Settings → Capabilities → Skills. The archive is the skill folder itself (top-level bd-income-tax/ with SKILL.md inside), so no manual zipping is needed — do not use GitHub's "Source code" zip, which wraps everything in the repo root.
  • OpenAI Codex CLI: place skills/bd-income-tax/ under ~/.agents/skills/.
  • Gemini CLI / Antigravity: place under ~/.gemini/... (CLI) or .agent/skills/.
  • Clone & copy: git clone this repo and copy skills/bd-income-tax/ into your agent's skills directory.

The consumer ChatGPT and Gemini apps do not load SKILL.md; a GPT/Gem front-end would need to link out to this repo for the full dataset.

Updating

When a newer release is published, update in Claude Code by running these one at a time (slash commands only run when entered on their own, not pasted together):

/plugin marketplace update bd-income-tax-skills
/plugin update bd-income-tax@bd-income-tax-skills

The first refreshes the marketplace from GitHub; the second installs the new version. Confirm the version under /plugin → Marketplaces, or against the CHANGELOG.

For the desktop / Claude.ai route, re-download the latest bd-income-tax.zip from the latest release and re-upload it under Settings → Capabilities → Skills.

How this was built

This skill was authored with AI assistance (Claude Code). Every rate, threshold, and figure is grounded in the cited sources in references/sources.md and verified by the deterministic calculator's self-tests — not produced free-hand. Corrections and source updates are welcome; see CONTRIBUTING.md.

Disclaimer

Informational only; not professional tax advice. Verify against the current gazetted Finance Act 2026 and NBR circulars (nbr.gov.bd). Individual/personal tax scope only — not corporate tax or VAT.

License

MIT.