GovData Docs

GovData API Documentation

One API for UK Government reference data. Tax rates, bank holidays, and more — through a single, consistent REST API.

Install

# No installation needed — just use your API key
curl -H "Authorization: Bearer YOUR_API_KEY" \
  https://api.govdata.dev/v1/tax/income/bands

Get started in 3 steps

1

Create an account

Sign up at console.govdata.dev to get your API key.

2

Grab your key

Copy your test key (gd_test_...) from the dashboard.

3

Make a request

Send your first API call. See the quick start guide.

Available APIs

Tax API

Income tax bands, NI thresholds, take-home calculator. Covers England, Wales, Scotland, and NI.

GET /v1/tax/income/bands POST /v1/tax/income/calculate POST /v1/tax/take-home/calculate

Calendar API

UK bank holidays by region and year. Covers England & Wales, Scotland, and Northern Ireland.

GET /v1/calendar/bank-holidays GET /v1/calendar/bank-holidays/next GET /v1/calendar/regions

Companies API

5M+ UK companies. Search by name, filter by status, SIC code, or postcode. Powered by Companies House data.

GET /v1/companies/search GET /v1/companies/:number GET /v1/companies/statistics

Integrations

MCP (AI Assistants)

Connect Claude and other AI assistants to GovData. Ask tax, company, and calendar questions in natural language.

11 tools 15 resources 3 prompts

Guides

Quick Start

From sign-up to first API call in under 2 minutes

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Authentication

API keys, Bearer tokens, test vs live environments

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Rate Limits

Understanding rate limits, credits, and retry headers

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Error Reference

Error codes, messages, and troubleshooting

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Base URL: https://api.govdata.dev/v1

Contains public sector information licensed under the Open Government Licence v3.0.