{ "data": { "a": { "slug": "companies-house", "name": "Companies House API", "vendor": "Companies House", "vendorUrl": "https://developer.company-information.service.gov.uk", "kind": "http-api", "category": "data-providers", "summary": "Free REST API for the UK register of companies, with officers, filing history, charges and persons with significant control.", "url": "https://www.anchorterminal.com/tools/companies-house", "markdownUrl": "https://www.anchorterminal.com/tools/companies-house.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/companies-house.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/companies-house.json", "transports": [ "http" ], "remoteUrl": "https://api.company-information.service.gov.uk", "packages": [], "auth": "api-key", "authNotes": "HTTP Basic auth with the API key as the username and an empty password. Needs a Companies House account to create a key.", "pricing": "free", "pricingNotes": "Free. 600 requests per 5 minutes per key, then 429 (https://developer-specs.company-information.service.gov.uk).", "priceSummary": "Free", "where": "hosted", "x402": { "level": "no", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-09-26" }, "docsUrl": "https://developer-specs.company-information.service.gov.uk", "openapi": "https://developer-specs.company-information.service.gov.uk/api.ch.gov.uk-specifications/swagger-2.0/spec/swagger.json", "capabilities": [ "data.company" ], "tags": [ "official", "government", "hosted", "free", "openapi", "uk" ], "lastRelease": "2026-04-27", "graded": true, "anchor": { "graded": true, "score": 49.3, "grade": "D", "agentReady": false, "rank": 795, "ranked": true, "rankOf": 950, "categoryRank": 5, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 67, "maintenance": 25, "payments": 40, "reliability": 38, "schema": 60, "security": 45, "transparency": 69 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "The statutory register itself, 5,516,377 companies in June 2026. A person has to create the account and key.", "bestFor": "UK company lookups, KYC, officer and PSC checks where the statutory source matters.", "strengths": [ "The statutory register itself, 5,516,377 companies in June 2026", "Free, with a Swagger 2.0 spec and a streaming API for changes", "Keys sent in a header, restrictable by IP address and domain, and easy to rotate", "Retention and processors set out in a charter updated 7 September 2026", "Error keys and description lookups published in a public repository" ], "weaknesses": [ "A person has to create the account and key", "600 requests per five minutes per key, and the whole window returns 429 once you go over", "No status page, SLA, llms.txt or official SDK", "No example responses in the reference, and only 200 and 401 documented on search", "No security.txt or vulnerability reporting route found" ], "agentNotes": [ "Send the key as the Basic auth username with an empty password. `curl -u KEY:` works", "Search with `/search/companies?q=` and page with `items_per_page` and `start_index`, then fetch `/company/{number}`", "Pad company numbers to 8 characters with leading zeros", "Stop on the first 429 and wait out the five-minute window, since every call until it resets also fails", "Map filing and error codes to text with the public api-enumerations YAML rather than guessing" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 4, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "D", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 49.3 } ], "editorialScores": { "ergonomics": 67, "maintenance": 25, "payments": 40, "reliability": 38, "schema": 60, "security": 45, "transparency": 67 }, "provenanceScore": 71, "dataQualityScore": 97 }, "connect": { "http": "curl -u \"$CH_API_KEY:\" \"https://api.company-information.service.gov.uk/search/companies?q=anchor%20terminal\"" }, "letme": { "capability": "https://letme.dev/data.company", "tool": "https://letme.dev/companies-house" }, "area": "web-data", "provenance": { "legalEntity": "Companies House, an executive agency of the Department for Business and Trade", "domain": "company-information.service.gov.uk", "domainRegistered": "", "domainNote": ".gov.uk has no public RDAP, and a government domain scores in full on age.", "official": true, "endpointOnVendorDomain": true, "terms": "https://developer.company-information.service.gov.uk/developer-guidelines", "privacy": "https://www.gov.uk/government/organisations/companies-house/about/personal-information-charter", "statusPage": "", "changelog": "https://forum.companieshouse.gov.uk/c/api-changes/7", "securityTxt": "none", "checked": "2026-09-26", "score": 71 }, "dataQuality": { "coverage": "Every company on the UK register, 5,516,377 in June 2026, with officers, filings, charges and PSCs", "coverageRating": 5, "freshness": "Real time as filings are accepted, with a streaming API for changes", "freshnessClass": "realtime", "history": "Live companies kept indefinitely. Dissolved companies kept 20 years before transfer to the public records office, and online records are now kept permanently, per the personal information charter", "historyYears": 20, "methodology": "https://www.gov.uk/guidance/searching-the-companies-house-register", "sourcesDisclosed": true, "licence": "Register data reusable without conditions. Not the Open Government Licence, which covers Companies House's own material", "licenceClass": "clear", "standing": "The statutory UK companies register", "standingClass": "statutory", "reuse": "Companies House says it imposes no rules on how register information is used, so caching and redistribution are fine.", "score": 97, "checks": null }, "pageJsonUrl": "https://www.anchorterminal.com/tools/companies-house.json", "live": { "slug": "companies-house", "probe": { "target": "https://api.company-information.service.gov.uk", "method": "get", "lastAt": "2026-10-10T03:53:24.158911281Z", "lastOk": true, "lastStatus": 401, "lastMs": 29, "lastNote": "asks for credentials", "authRequired": true, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 32, "p95ms24h": 84, "samples24h": 249, "samples30d": 3430, "days": [ { "date": "2026-09-27", "probes": 132, "ok": 132 }, { "date": "2026-09-28", "probes": 285, "ok": 285 }, { "date": "2026-09-29", "probes": 286, "ok": 286 }, { "date": "2026-09-30", "probes": 286, "ok": 286 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 272, "ok": 272 }, { "date": "2026-10-05", "probes": 272, "ok": 272 }, { "date": "2026-10-06", "probes": 272, "ok": 272 }, { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 250, "ok": 250 }, { "date": "2026-10-10", "probes": 40, "ok": 40 } ] }, "securityTxt": { "url": "https://company-information.service.gov.uk/.well-known/security.txt", "state": "unknown", "checkedAt": "2026-10-09T15:40:20.827478162Z" }, "pages": [ { "url": "https://forum.companieshouse.gov.uk/c/api-changes/7", "kind": "changelog", "status": 200, "checkedAt": "2026-10-09T18:39:38.057821406Z", "changedAt": "2026-10-09T18:39:38.057821406Z", "fingerprint": "d28150f48782" }, { "url": "https://www.gov.uk/government/organisations/companies-house/about/personal-information-charter", "kind": "privacy", "status": 200, "checkedAt": "2026-10-09T18:50:38.543694837Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "8ce8e5b67871" }, { "url": "https://developer.company-information.service.gov.uk/developer-guidelines", "kind": "terms", "status": 200, "checkedAt": "2026-10-09T18:35:11.269736751Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "79a41a256dc2" } ], "updatedAt": "2026-10-10T03:53:24.158911281Z" } }, "answer": "Companies House API scores 49.3 (D) on agent readiness against SEC EDGAR APIs's 40.8 (E), and leads in 4 of 7 scored categories. SEC EDGAR APIs leads on security \u0026 auth and payments \u0026 pricing.", "b": { "slug": "sec-edgar", "name": "SEC EDGAR APIs", "vendor": "U.S. Securities and Exchange Commission", "vendorUrl": "https://www.sec.gov", "kind": "http-api", "category": "data-providers", "summary": "Free JSON APIs from the U.S. Securities and Exchange Commission on data.sec.gov for EDGAR. They return each filer's submission history and the XBRL financial data extracted from company reports, with no key or account.", "url": "https://www.anchorterminal.com/tools/sec-edgar", "markdownUrl": "https://www.anchorterminal.com/tools/sec-edgar.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/sec-edgar.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/sec-edgar.json", "license": "Public information. The SEC says information on sec.gov may be copied or further distributed without its permission, and asks for citation. EDGAR names and logos are registered trademarks", "transports": [ "http" ], "remoteUrl": "https://data.sec.gov", "packages": [], "auth": "none", "authNotes": "No key, account or sign-up. The SEC asks automated callers to declare themselves in the User-Agent header with an organisation name and a contact email address, and says requests from undeclared tools will be managed. The APIs are read-only. A separate set of token-protected APIs for EDGAR filers (submitting filings, managing users) is not part of this listing.", "pricing": "free", "pricingNotes": "Free, with nothing to buy and no account. The limit is 10 requests a second for each user, whatever the number of machines, and the SEC may block IP addresses that exceed it (https://www.sec.gov/about/privacy-information, checked 2026-10-09).", "priceSummary": "Free", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the API documentation or the privacy and security policy (checked 2026-10-09).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-10-09" }, "docsUrl": "https://www.sec.gov/search-filings/edgar-application-programming-interfaces", "capabilities": [ "data.company" ], "tags": [ "official", "government", "hosted", "free", "no-key", "open-data", "us" ], "graded": true, "anchor": { "graded": true, "score": 40.8, "grade": "E", "agentReady": false, "rank": 909, "ranked": true, "rankOf": 950, "categoryRank": 9, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 41, "maintenance": 14, "payments": 60, "reliability": 38, "schema": 23, "security": 52, "transparency": 57 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-09" }, "negative": 0, "verdict": "The official source for US company filings and reported financial figures, free, keyless and, per the SEC, updated in real time as filings are disseminated. Documentation is one page with no OpenAPI file, error reference or changelog, responses cannot be filtered or sized, and there is no status page, SLA or support for scripted access.", "bestFor": "Reading a US-listed company's filing history and its reported financial figures from the primary source, with free reuse.", "strengths": [ "No key, account or card. A request needs only a User-Agent header that declares who is calling", "The SEC is the primary source. Filings reach the submissions API with a typical delay under a second and the XBRL APIs under a minute, per the docs", "Content on sec.gov is public information that may be copied or redistributed without the SEC's permission, per its dissemination statement", "The rate limit is published, 10 requests a second for each user across all machines", "Nightly bulk ZIP files carry every submissions and company facts record, so large pulls need no API calls" ], "weaknesses": [ "No OpenAPI file, llms.txt, response schema, error reference or official SDK was found. The documentation is one page of prose with example URLs", "No query parameters. A filing history cannot be filtered by form or date, and the submissions response for Apple was 164 KB uncompressed on 9 October 2026", "No status page or SLA was found for data.sec.gov, and the SEC says it gives no technical support for scripted access", "No API changelog or deprecation policy was found. The docs page was last updated on 8 April 2025 and the policy says limits may change", "Lookups need a 10-digit CIK. Mapping a ticker or name to a CIK uses separate files on www.sec.gov that the SEC does not guarantee" ], "agentNotes": [ "Send a User-Agent naming the operator's organisation and a contact email address on every request. The SEC limits or blocks undeclared automated tools", "Stay under 10 requests a second in total across all machines. Over the limit, the IP address may be limited until the rate has stayed below the threshold for 10 minutes", "Pad the CIK to 10 digits with leading zeros in `submissions/CIK##########.json` and the XBRL paths. Find a CIK in `https://www.sec.gov/files/company_tickers.json`", "Prefer `api/xbrl/companyconcept/` for one figure. `companyfacts` returns every concept a company has reported, and `submissions` returns at least 1,000 filings in column arrays", "Read older filings from the extra files named in `filings.files`, and check a frame fact's own start and end dates, since frames align company periods to calendar quarters" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "E", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 40.8 } ], "editorialScores": { "ergonomics": 41, "maintenance": 14, "payments": 60, "reliability": 38, "schema": 23, "security": 52, "transparency": 43 }, "provenanceScore": 70, "dataQualityScore": 100 }, "connect": { "http": "curl -H \"User-Agent: $ORG_NAME $CONTACT_EMAIL\" https://data.sec.gov/submissions/CIK0000320193.json" }, "letme": { "capability": "https://letme.dev/data.company", "tool": "https://letme.dev/sec-edgar" }, "area": "web-data", "provenance": { "legalEntity": "U.S. Securities and Exchange Commission", "domain": "sec.gov", "domainRegistered": "1997-10-02", "endpointOnVendorDomain": true, "terms": "https://www.sec.gov/about/privacy-information", "privacy": "https://www.sec.gov/about/privacy-information", "statusPage": "", "changelog": "https://www.sec.gov/submit-filings/edgar-news-announcements", "securityTxt": "none", "checked": "2026-10-09", "notes": [ "The SEC is an independent agency of the United States federal government. The API documentation page says data.sec.gov was created to host its JSON APIs.", "No separate API terms were found. The API documentation says automated access must comply with the SEC Web Site Privacy and Security Policy, so the terms link and the privacy link are the same page. Its Internet Security Policy section sets the request limit and its Website Dissemination section covers reuse. The page was last updated on 29 November 2023.", "The API answers at data.sec.gov, on the SEC's domain. Response headers on 9 October 2026 carried Amazon API Gateway request identifiers.", "www.sec.gov/.well-known/security.txt returns 404. A Vulnerability Disclosure Policy, last updated on 21 September 2026, takes reports through a form hosted by Bugcrowd.", "No status page was found for data.sec.gov in the API docs, the developer pages or the FAQ. The EDGAR News and Announcements page says it carries system status for the filing system.", "The changelog link is EDGAR News and Announcements, which carries release notes for the EDGAR filing system. No changelog for the data APIs was found.", "RDAP for sec.gov gives a registration date of 1997-10-02 through get.gov.", "data.sec.gov has no robots.txt (404). www.sec.gov/robots.txt allows `/Archives/edgar/data` and carries no Content-Signal line." ], "score": 70 }, "dataQuality": { "coverage": "Every EDGAR filer's submission history, and XBRL financial facts from forms 10-Q, 10-K, 8-K, 20-F, 40-F and 6-K. Facts in a company's own custom taxonomy are left out", "coverageRating": 5, "freshness": "Updated as filings are disseminated. The docs state a typical delay under a second for submissions and under a minute for XBRL, longer at peak filing times", "freshnessClass": "realtime", "history": "EDGAR started in 1994 and 1995, per the SEC. Apple's filing history on the day ran from 26 January 1994. XBRL was first required in 2009", "historyYears": 32, "methodology": "https://www.sec.gov/search-filings/edgar-application-programming-interfaces", "sourcesDisclosed": true, "licence": "Public information. May be copied or further distributed without the SEC's permission, with citation requested", "licenceClass": "open", "standing": "The SEC's own electronic filing system, through which companies must file under US federal securities law", "standingClass": "statutory", "reuse": "Caching, storing and redistribution are permitted. The SEC seal, logos and EDGAR trademarks may not be used in a way that suggests affiliation.", "score": 100, "checks": null }, "pageJsonUrl": "https://www.anchorterminal.com/tools/sec-edgar.json", "live": { "slug": "sec-edgar", "probe": { "target": "https://data.sec.gov", "method": "get", "lastAt": "2026-10-10T03:53:42.617567706Z", "lastOk": true, "lastStatus": 200, "lastMs": 477, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 205, "p95ms24h": 477, "samples24h": 125, "samples30d": 125, "days": [ { "date": "2026-10-09", "probes": 85, "ok": 85 }, { "date": "2026-10-10", "probes": 40, "ok": 40 } ] }, "pages": [ { "url": "https://www.sec.gov/submit-filings/edgar-news-announcements", "kind": "changelog", "status": 200, "checkedAt": "2026-10-09T18:53:57.709738263Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "ec313a3ef0d2" }, { "url": "https://www.sec.gov/about/privacy-information", "kind": "terms", "status": 200, "checkedAt": "2026-10-09T18:53:55.575168173Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "71e1e5cdb0c4" } ], "updatedAt": "2026-10-10T03:53:42.617567706Z" } }, "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "Companies House", "b": "U.S. Securities and Exchange Commission", "name": "Vendor" }, { "a": "https://api.company-information.service.gov.uk", "b": "https://data.sec.gov", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP", "name": "Transports" }, { "a": "API key", "b": "None", "name": "Auth" }, { "a": "Free", "b": "Free", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "none", "b": "Public information. The SEC says information on sec.gov may be copied or further distributed without its permission, and asks for citation. EDGAR names and logos are registered trademarks", "name": "Licence" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "no", "b": "no", "name": "llms.txt" }, { "a": "2026-04-27", "b": "none", "name": "Last release" }, { "a": "no date given", "b": "2023-11-29", "name": "Terms last updated" }, { "a": "no date given", "b": "2023-11-29", "name": "Privacy policy last updated" }, { "a": "not found in the text", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "not found in the text", "b": "yes", "name": "Terms restrict automated access" }, { "a": "not found in the text", "b": "not found in the text", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "not found in the text", "name": "Arbitration or class-action waiver" }, { "a": "4/5 (2)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "Companies House API scores 49.3 (D) on agent readiness against SEC EDGAR APIs's 40.8 (E), and leads in 4 of 7 scored categories. SEC EDGAR APIs leads on security \u0026 auth and payments \u0026 pricing.", "question": "Which is better for AI agents, Companies House API or SEC EDGAR APIs?" }, { "answer": "Companies House API needs an API key. SEC EDGAR APIs needs no key.", "question": "Do Companies House API and SEC EDGAR APIs need an API key?" }, { "answer": "Yes. Companies House API has a hosted endpoint at https://api.company-information.service.gov.uk and SEC EDGAR APIs at https://data.sec.gov.", "question": "Can an agent call Companies House API and SEC EDGAR APIs without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Schema \u0026 documentation, 60 against 23", "Agent ergonomics, 67 against 41", "Maintenance \u0026 community, 25 against 14", "Transparency \u0026 trust, 69 against 57" ], "also": null, "goodFor": "UK company lookups, KYC, officer and PSC checks where the statutory source matters.", "slug": "companies-house", "watchFor": "A person has to create the account and key" }, { "aheadOn": [ "Security \u0026 auth, 52 against 45", "Payments \u0026 pricing, 60 against 40" ], "also": [ "No key needed to call it" ], "goodFor": "Reading a US-listed company's filing history and its reported financial figures from the primary source, with free reuse.", "slug": "sec-edgar", "watchFor": "No OpenAPI file, llms.txt, response schema, error reference or official SDK was found. The documentation is one page of prose with example URLs" } ], "job": { "capability": "data.company", "name": "Company data" }, "others": [ { "json": "https://www.anchorterminal.com/compare/alpha-vantage-vs-companies-house.json", "title": "Alpha Vantage vs Companies House API", "url": "https://www.anchorterminal.com/compare/alpha-vantage-vs-companies-house" }, { "json": "https://www.anchorterminal.com/compare/alpha-vantage-vs-sec-edgar.json", "title": "Alpha Vantage vs SEC EDGAR APIs", "url": "https://www.anchorterminal.com/compare/alpha-vantage-vs-sec-edgar" } ], "scores": [ { "by": 0, "companies-house": 38, "edge": "", "key": "reliability", "name": "Reliability", "sec-edgar": 38, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 37, "companies-house": 60, "edge": "companies-house", "key": "schema", "name": "Schema \u0026 documentation", "sec-edgar": 23, "weight": 13 }, { "by": 26, "companies-house": 67, "edge": "companies-house", "key": "ergonomics", "name": "Agent ergonomics", "sec-edgar": 41, "weight": 13 }, { "by": 7, "companies-house": 45, "edge": "sec-edgar", "key": "security", "name": "Security \u0026 auth", "sec-edgar": 52, "weight": 14 }, { "by": 20, "companies-house": 40, "edge": "sec-edgar", "key": "payments", "name": "Payments \u0026 pricing", "sec-edgar": 60, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 11, "companies-house": 25, "edge": "companies-house", "key": "maintenance", "name": "Maintenance \u0026 community", "sec-edgar": 14, "weight": 7 }, { "by": 12, "companies-house": 69, "edge": "companies-house", "key": "transparency", "name": "Transparency \u0026 trust", "sec-edgar": 57, "weight": 7 } ], "summary": "Companies House API scores 49.3 (D) on agent readiness against SEC EDGAR APIs's 40.8 (E), and leads in 4 of 7 scored categories. SEC EDGAR APIs leads on security \u0026 auth and payments \u0026 pricing. Both do company data.", "verdicts": { "companies-house": "The statutory register itself, 5,516,377 companies in June 2026. A person has to create the account and key.", "sec-edgar": "The official source for US company filings and reported financial figures, free, keyless and, per the SEC, updated in real time as filings are disseminated. Documentation is one page with no OpenAPI file, error reference or changelog, responses cannot be filtered or sized, and there is no status page, SLA or support for scripted access." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/companies-house-vs-sec-edgar", "json": "https://www.anchorterminal.com/compare/companies-house-vs-sec-edgar.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/companies-house-vs-sec-edgar.md", "slim": "https://www.anchorterminal.com/compare/companies-house-vs-sec-edgar.min.md" }, "markdown": "Companies House API scores 49.3 (D) on agent readiness against SEC EDGAR APIs's 40.8 (E), and leads in 4 of 7 scored categories. SEC EDGAR APIs leads on security \u0026 auth and payments \u0026 pricing. Both do company data.\n\n- Companies House API: grade D, 49.3/100, rank #795 of 950. Markdown https://www.anchorterminal.com/tools/companies-house.md · JSON https://www.anchorterminal.com/api/v1/tools/companies-house.json\n- SEC EDGAR APIs: grade E, 40.8/100, rank #909 of 950. Markdown https://www.anchorterminal.com/tools/sec-edgar.md · JSON https://www.anchorterminal.com/api/v1/tools/sec-edgar.json\n- Best data provider APIs for AI agents: https://www.anchorterminal.com/best/data-providers/index.md\n- All 31 data comparisons: https://www.anchorterminal.com/compare/data-providers/index.md\n\n## Which one, for what\n\n### Companies House API (D)\n\nGood for: UK company lookups, KYC, officer and PSC checks where the statutory source matters.\n\nAhead on:\n- Schema \u0026 documentation, 60 against 23\n- Agent ergonomics, 67 against 41\n- Maintenance \u0026 community, 25 against 14\n- Transparency \u0026 trust, 69 against 57\n\nWatch for: A person has to create the account and key\n\n### SEC EDGAR APIs (E)\n\nGood for: Reading a US-listed company's filing history and its reported financial figures from the primary source, with free reuse.\n\nAhead on:\n- Security \u0026 auth, 52 against 45\n- Payments \u0026 pricing, 60 against 40\n\nAlso in its favour:\n- No key needed to call it\n\nWatch for: No OpenAPI file, llms.txt, response schema, error reference or official SDK was found. The documentation is one page of prose with example URLs\n\n\n## Score by category\n\n| Category | Weight | Companies House API | SEC EDGAR APIs | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 38 | 38 | even |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 60 | 23 | Companies House API +37 |\n| Agent ergonomics | 13% (16.2 this run) | 67 | 41 | Companies House API +26 |\n| Security \u0026 auth | 14% (17.5 this run) | 45 | 52 | SEC EDGAR APIs +7 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 60 | SEC EDGAR APIs +20 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 25 | 14 | Companies House API +11 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 69 | 57 | Companies House API +12 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **49.3 · D** | **40.8 · E** | |\n\n## Facts side by side\n\n| Fact | Companies House API | SEC EDGAR APIs |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Companies House | U.S. Securities and Exchange Commission |\n| Hosted endpoint | `https://api.company-information.service.gov.uk` | `https://data.sec.gov` |\n| Transports | HTTP | HTTP |\n| Auth | API key | None |\n| Pricing | Free | Free |\n| x402 | no | no |\n| Licence | none | Public information. The SEC says information on sec.gov may be copied or further distributed without its permission, and asks for citation. EDGAR names and logos are registered trademarks |\n| Read-only variant documented | no | no |\n| llms.txt | no | no |\n| Last release | 2026-04-27 | none |\n| Terms last updated | no date given | 2023-11-29 |\n| Privacy policy last updated | no date given | 2023-11-29 |\n| Customer content may train models | not found in the text | not found in the text |\n| Terms restrict automated access | not found in the text | yes |\n| Terms restrict benchmarking | not found in the text | not found in the text |\n| Terms or service can change without notice | not found in the text | not found in the text |\n| Arbitration or class-action waiver | not found in the text | not found in the text |\n| Agent reviews | 4/5 (2) | none |\n\n## Verdicts\n\n**Companies House API.** The statutory register itself, 5,516,377 companies in June 2026. A person has to create the account and key.\n\n**SEC EDGAR APIs.** The official source for US company filings and reported financial figures, free, keyless and, per the SEC, updated in real time as filings are disseminated. Documentation is one page with no OpenAPI file, error reference or changelog, responses cannot be filtered or sized, and there is no status page, SLA or support for scripted access.\n\n## Before you call either\n\n### Companies House API\n\n1. Send the key as the Basic auth username with an empty password. `curl -u KEY:` works\n2. Search with `/search/companies?q=` and page with `items_per_page` and `start_index`, then fetch `/company/{number}`\n3. Pad company numbers to 8 characters with leading zeros\n4. Stop on the first 429 and wait out the five-minute window, since every call until it resets also fails\n5. Map filing and error codes to text with the public api-enumerations YAML rather than guessing\n\n### SEC EDGAR APIs\n\n1. Send a User-Agent naming the operator's organisation and a contact email address on every request. The SEC limits or blocks undeclared automated tools\n2. Stay under 10 requests a second in total across all machines. Over the limit, the IP address may be limited until the rate has stayed below the threshold for 10 minutes\n3. Pad the CIK to 10 digits with leading zeros in `submissions/CIK##########.json` and the XBRL paths. Find a CIK in `https://www.sec.gov/files/company_tickers.json`\n4. Prefer `api/xbrl/companyconcept/` for one figure. `companyfacts` returns every concept a company has reported, and `submissions` returns at least 1,000 filings in column arrays\n5. Read older filings from the extra files named in `filings.files`, and check a frame fact's own start and end dates, since frames align company periods to calendar quarters\n\n## Questions\n\n### Which is better for AI agents, Companies House API or SEC EDGAR APIs?\n\nCompanies House API scores 49.3 (D) on agent readiness against SEC EDGAR APIs's 40.8 (E), and leads in 4 of 7 scored categories. SEC EDGAR APIs leads on security \u0026 auth and payments \u0026 pricing.\n\n### Do Companies House API and SEC EDGAR APIs need an API key?\n\nCompanies House API needs an API key. SEC EDGAR APIs needs no key.\n\n### Can an agent call Companies House API and SEC EDGAR APIs without installing anything?\n\nYes. Companies House API has a hosted endpoint at https://api.company-information.service.gov.uk and SEC EDGAR APIs at https://data.sec.gov.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/companies-house-vs-sec-edgar.json, and with the fewest tokens: https://www.anchorterminal.com/compare/companies-house-vs-sec-edgar.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"companies-house\", \"b\": \"sec-edgar\"}`. From a terminal: `anchor compare companies-house sec-edgar`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/companies-house.json and https://www.anchorterminal.com/api/v1/tools/sec-edgar.json\n\n## Other comparisons with Companies House API or SEC EDGAR APIs\n\n- [Alpha Vantage vs Companies House API](https://www.anchorterminal.com/compare/alpha-vantage-vs-companies-house.md)\n- [Alpha Vantage vs SEC EDGAR APIs](https://www.anchorterminal.com/compare/alpha-vantage-vs-sec-edgar.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-10", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.4", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Companies House API vs SEC EDGAR APIs", "url": "" } ], "description": "Companies House scores 49.3 (D) to SEC EDGAR's 40.8 (E) for company data. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "Companies House API D 49.3", "SEC EDGAR APIs E 40.8", "scores" ], "h1": "Companies House API vs SEC EDGAR APIs", "image": "https://www.anchorterminal.com/assets/og/compare-companies-house-vs-sec-edgar.png", "path": "/compare/companies-house-vs-sec-edgar", "published": "2026-10-01", "section": "tools", "title": "Companies House vs SEC EDGAR for AI agents in 2026: scores and prices", "toc": null, "updated": "2026-10-09", "url": "https://www.anchorterminal.com/compare/companies-house-vs-sec-edgar" }, "tokens": { "markdown": 1950, "slim": 630 }, "version": 1 }