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verify-polish-company

Verify Polish companies and contractors by NIP, KRS, or REGON; check VAT status and bank accounts against the Ministry of Finance White List (Biała Lista)…

Skill by bartosz-kuc

IndexedMIT
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Install

Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/bartosz-kuc-verify-polish-company

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

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About

Verify Polish companies and contractors by NIP, KRS, or REGON; check VAT status and bank accounts against the Ministry of Finance White List (Biała Lista); look up REGON/GUS registry data; read KRS registry data; and validate EU VAT numbers via VIES. Uses skanfirmy.pl's free, public API — no API key and no registration (per-IP rate limits apply). Use whenever the user needs to check a Polish business, a tax ID (NIP), a KRS number, a REGON, a counterparty's VAT status or bank account, or an EU VAT number (VIES).

Use cases: backend, data, finance

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Permissions

What this skill can do and what it asks for, from its SKILL.md and code. Checked Nov 2, 2026.

Tools
No tools found
Secrets
None asked for
Install scripts
None found

Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/verify-polish-company

What's inside

Skill name
verify-polish-company
Description
Verify Polish companies and contractors by NIP, KRS, or REGON; check VAT status and bank accounts against the Ministry of Finance White List (Biała Lista); look up REGON/GUS registry data; read KRS registry data; and validate EU VAT numbers via VIES. Uses skanfirmy.pl's free, public API — no API key and no registration (per-IP rate limits apply). Use whenever the user needs to check a Polish business, a tax ID (NIP), a KRS number, a REGON, a counterparty's VAT status or bank account, or an EU VAT number (VIES).
License
MIT
Instructions
124 lines in SKILL.md · view on GitHub

Before installing

  • Instructions call the network

Agent Skills spec issues

  • name: "verify-polish-company" does not match folder "skill"

Files (3)

  • LICENSE
  • README.md
  • SKILL.md

SKILL.md (first lines)

# Verify a Polish company (skanfirmy.pl)

This skill verifies Polish businesses straight from official government
registers (Ministry of Finance, Ministry of Justice / KRS, Statistics Poland /
GUS, and the European Commission / VIES) through **skanfirmy.pl**, a free public
API. Every endpoint is a plain `GET` that returns JSON when you add
`?format=json`. **No API key, no account.** The service is meant for single,
user-driven lookups, not bulk data harvesting: REST allows at most 20 requests
per 10 seconds from one IP address (HTTP 429 for 10 seconds above that), the MCP
server 60 per 10 seconds.

**Sole traders and other natural persons (JDG, civil partnerships) get minimised
data** (GDPR): name, NIP, VAT status, town and the *number* of White List
accounts — no REGON, no address, no registration date, no PKD and no list of
account numbers. To check one specific account of such a counterparty, use
`POST /rachunek` (or the MCP tool `sprawdz_rachunek`). Companies (entities with a
KRS number) get full data.

## When to use it

Reach for this skill when the user asks to:

- check whether a Polish company is an **active VAT payer** or is VAT-exempt;
- verify that a **bank account** belongs to a contractor on the White List
  (needed for Polish "due diligence" on payments over 15 000 PLN);
- pull a company's **KRS** registry data (legal form, PKD, share capital,
  address, representation) by NIP or KRS number;
- look up **REGON** and official name/address of a company by NIP (for sole
  traders only the name, legal form, town and activity status);
- validate an **EU VAT number** (any member state) via **VIES**;
- check **many NIPs at once**.

`NIP` = 10-digit Polish tax ID. `KRS` = court-register number. `REGON` =
statistical register number. `VAT-UE`/VIES numbers are prefixed by a 2-letter
country code (e.g. `DE`, `IE`, `FR`).

## REST endpoints (GET, keyless)

Call these with any HTTP client (`curl`, `fetch`, `requests`, a web-fetch
tool). Append `?format=json` for machine-readable JSON; without it you get
crawlable HTML with embedded JSON-LD.

| Endpoint | What it returns |
|---|---|
| `GET https://skanfirmy.pl/nip/{nip}` | VAT status + White List (accounts) + KRS data + REGON, combined in one response (minimised for natural persons, see above) |
| `GET https://skanfirmy.pl/nips/{list}` | The same for **up to 30** comma-separated NIPs in one call (no KRS join) |
| `GET https://skanfirmy.pl/regon/{nip}` | REGON registry data: REGON number, official name, legal form, address (sole traders: name, form, town, activity status only) |
| `POST https://skanfirmy.pl/rachunek` | Is this bank account on the White List for this NIP? JSON body `{"nip": "…", "nrb": "…"}`; returns the Ministry's `accountAssigned` (`"TAK"`/`"NIE"`) and `requestId` |
| `GET https://skanfirmy.pl/vies/{country}/{number}` | Whether an EU VAT number is valid, plus the registered name/address |

Examples:

```bash
# Full check by NIP (VAT status + White List + KRS + REGON)
curl "https://skanfirmy.pl/nip/5260250995?format=json"

# REGON / GUS data only
curl "https://skanfirmy.pl/regon/5260250995?format=json"

# EU VAT number (VIES) — country code + number without the prefix
curl "https://skanfirmy.pl/vies/IE/6388047V?format=json"

# Many NIPs at once (comma-separated, up to 30)
curl "https://skanfirmy.pl/nips/5252344078,5260251049,7740001454?format=json"
```

`/regon/{nip}` returns a `dane` object. For a company: `regon`, `nazwa` (official
name), `typ` (`P` = legal person, `LP` = local unit) and address fields
(`wojewodztwo`, `powiat`, `gmina`, `miejscowosc`, `kodPocztowy`, `ulica`,
`nrNieruchomosci`, `nrLokalu`). For a natural person (`typ` `F`/`LF`, or a civil
partnership) only `nip`, `nazwa`, `typ`, `forma`, `miejscowosc` and `status`
(`active`/`ended`), with a `privacy` object that links to the official GUS search.

## Choosing the right endpoint

- Need VAT status **and** KRS in one shot → `/nip/{nip}`.
- Only official name/address/REGON of a company → `/regon/{nip}`.
- A **specific bank account** of a counterparty (also a sole trader) →
  `POST /rachunek`.
- A **foreign** EU counterparty's VAT number → `/vies/{country}/{number}`.
- A **list** of Polish counterparties → `/nips/{list}` (then, if you need KRS
  for a specific hit, re-query it with `/nip/{nip}`).

## Error handling

- Unknown entity → `404`. NIP with an invalid checksum → `400`. Handle both;
  do not assume every NIP has an entry.
- Too many requests → `429` (wait 10 seconds). The Ministry of Finance daily
  limit for the service exhausted → `503` with `Retry-After`.
- Some numbers are **restricted from presentation** (a data-protection
  procedure): the response is `200` with `restricted: true`, a fixed sentence and
  a link to the Ministry of Finance search, and no data. Tell the user to check
  the number there; do not treat it as "not registered".
- When comparing literal government values, key logic off the **original**
  Polish literals (VAT status `"Czynny"`/`"Zwolniony"`, account match
  `"TAK"`/`"NIE"`), not a translated label.

## MCP option (for MCP-capable agents)

If you speak the Model Context Protocol, connect to the server instead of
calling REST by hand:

`POST https://skanfirmy.pl/mcp` — stateless Streamable HTTP, JSON-RPC 2.0,
no key, 60 requests per 10 seconds from one IP address. Tools: `sprawdz_nip`, `sprawdz_lista_nip`, `sprawdz_regon`,
`sprawdz_vies`, `sprawdz_rachunek`, `generuj_mikrorachunek`, `szukaj_pkd`,
`oblicz_odsetki`, `szukaj_katalog_api`. A model-readable endpoint map lives at
`https://skanfirmy.pl/llms.txt`.

```bash
curl -s https://skanfirmy.pl/mcp \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"sprawdz_nip","arguments":{"nip":"5260250995"}}}'
```

## Source & disclaimer

Data comes directly from official registers — Ministry of Finance (VAT White
List), Ministry of Justice (KRS), Statistics Poland / GUS (REGON), and the
European Commission (VIES). skanfirmy.pl is an independent tool, not an official

From bartosz-kuc/skanfirmy-mcp, MIT.

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Last commit (this folder)
Sep 28, 2026 (1 month ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

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verify-polish-company skill. Agent Mart. https://agentmart.dev/skills/bartosz-kuc-verify-polish-company (last updated 2026-10-24)