Structured financials, director networks, and intelligent caching on top of Companies House. Stop wrestling with iXBRL and rate limits — get clean JSON in one call. Submit 500 companies as a batch and we handle the rest in the background.
No Companies House API key needed. One Registrum key covers everything.
# Request
curl -H "X-API-Key: reg_live_..." \
"https://api.registrum.co.uk/v1/company/00445790"
# Response
{
"company_name": "TESCO PLC",
"company_age_years": 104,
"turnover": 68190000000,
"accounts_overdue": false,
"credits_remaining": 49
}
Search any UK company. Click a result to see the full profile — financials, directors, and network.
Clean JSON for your app. Agent-ready Markdown for your LLM pipeline. MCP tools for Claude and Cursor. No Companies House API key required.
iXBRL filings parsed into clean JSON — turnover, net assets, profit/loss, employees. Current and prior year. All values in actual GBP. Explicit data_quality metadata explains exactly what's available and why.
See live data example →One endpoint traverses the full board network to 2 degrees. Returns all companies sharing directors, sorted by connection strength. Discover related entities that aren't obvious from a single filing.
See Tesco network →The PSC register decoded and made traversable. Natures of control translated to plain English ('Owns 75-100% of shares'). Active/ceased PSCs split automatically. Corporate entity PSCs include their company number — pass it to the chain endpoint to find the ultimate beneficial owner.
See ownership chain example →24h company profiles, 7-day financials. Stale-while-revalidate during CH outages — you get data even when Companies House is down. Never hit the 600-request rate limit again.
How it works →Name-to-number matching with optional enriched profiles on results. Pass enrich=true to return full company profiles in a single call — no second round-trip required.
Search API docs →Every response includes a summary_md field — pre-formatted GitHub Markdown ready to drop into an LLM prompt or agent context. No parsing, no post-processing.
## Codeweavers Limited **Net profit**: £4.6M (+94% YoY) **Net assets**: £9.2M **Employees**: 142See example output →
Install the MCP server once and your AI agent can look up any UK company directly. Works with Claude Desktop, Cursor, and any MCP-compatible client.
{
"mcpServers": {
"registrum": {
"command": "npx",
"args": ["-y", "@registrum/mcp"]
}
}
}Setup guide →Submit up to 500 company numbers in one POST. We enrich them in the background, automatically managing the CH API rate limit. Poll for results — no timeouts, no rate-limit errors, no queuing logic on your side.
POST /v1/batch
{"company_numbers": ["00445790", ...]}
→ {"batch_id": "3fa85f64-...", "status": "queued"}How it works →The raw Companies House API returns about 10 fields. A Registrum response returns over 28 — with financial data, computed fields, and infrastructure built in.
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# 50 free calls per month X-API-Key: reg_live_...
Pass the API key in the header. Any HTTP client works — curl, Python, Node, whatever you use.
curl -H "X-API-Key: reg_live_..." \
"https://api.registrum.co.uk/v1/company/00445790"JSON back in milliseconds. Cached, enriched, with explicit metadata about what's available.
{
"company_name": "TESCO PLC",
"turnover": 68190000000
}Copy-paste examples for the languages you already use.
import requests
res = requests.get(
"https://api.registrum.co.uk/v1/company/00445790",
headers={"X-API-Key": "rg_live_..."},
)
print(res.json())const res = await fetch(
"https://api.registrum.co.uk/v1/company/00445790",
{ headers: { "X-API-Key": "rg_live_..." } }
);
const data = await res.json();
console.log(data);curl -H "X-API-Key: rg_live_..." \ "https://api.registrum.co.uk/v1/company/00445790"
// claude_desktop_config.json
{
"mcpServers": {
"registrum": {
"command": "npx",
"args": ["-y", "@registrum/mcp"],
"env": {
"REGISTRUM_API_KEY": "rg_live_..."
}
}
}
}No setup fees. No hidden costs. Upgrade or cancel any time.
Beta access — use code BETA3 at checkout for 3 months free on Pro. First 20 sign-ups only.
50 free calls per month. Your key arrives in your inbox in seconds. No credit card required.
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