Nesu API

Find Portuguese companies by name or NIF, then retrieve their address, activity, legal structure, and available debt brackets. You use one API key to access company data and monitor your account’s usage.

Search by name or NIF — find up to 20 directory matches with normalized company-name search or an exact NIF query.
Retrieve company details — get the company’s legal name, address, primary CAE, share capital, and available tax and social-security debt brackets.
Cached company lookups — receive stored details for records less than six days old, with an upstream refresh for missing or older records.
Monitor your usage — check your included allowance, purchased credits, and remaining rate-limit capacity without spending a credit.

Your first company lookup

You need an active API key, available rate-limit capacity, and a credit to run this example. Set NESU_API_KEY to your full key, including the nesu_ prefix. The quickstart walks you through setup.

curl --fail-with-body --silent --show-error \
  --header "Authorization: Bearer $NESU_API_KEY" \
  'https://api.nesu.pt/api/v1/companies/509442013'

You receive a JSON response with result: "success" and the company’s details in data. This example uses illustrative fixture data, not a live company record or debt report:

{
  "result": "success",
  "data": {
    "nif": 509442013,
    "title": "Exemplo, Lda",
    "address": "Rua de Exemplo, 1",
    "zipcode": "1000-001",
    "city": "Lisboa",
    "activity": "Atividade de exemplo",
    "status": "",
    "cae": "",
    "structure": {
      "nature": "Sociedade por quotas",
      "capital": "5000.00",
      "capital_currency": "EUR"
    },
    "tax_debt": {
      "start": 10000,
      "end": 50000,
      "last_updated": "2026-09-15"
    },
    "social_security_debt": null
  }
}

Each admitted company search or lookup consumes one credit, including requests that later fail. Your API keys share your account’s credits and rate limit.

Explore the docs

Quickstart

Create your key, check usage, and make your first company requests.

API Reference

Explore endpoint parameters, response fields, and request examples.

Authentication

Authenticate requests and manage your API keys.

Errors

Understand problem responses and resolve failed requests.

Limits and credits

Understand allowances, shared limits, and retry headers.

Account usage

Read your plan, credit balance, quotas, and reset time.

Getting Started

Guides

Your first company lookup

Explore the docs

Quickstart

API Reference

Authentication

Errors

Limits and credits

Account usage

​Your first company lookup

​Explore the docs

Quickstart

API Reference

Authentication

Errors

Limits and credits

Account usage

Your first company lookup

Explore the docs