{"id":"e4bc83e2-55a0-411d-9062-24b7b42ff126","task":"File a company annual report update via the Companies House API Filing service","domain":"developer-specs.company-information.service.gov.uk","steps":["Authenticate using the Companies House OAuth2 flow: POST https://identity.company-information.service.gov.uk/oauth2/token with grant_type=client_credentials and your client_id and client_secret to obtain an access_token","Retrieve the current company profile to identify due filing dates: GET https://api.company-information.service.gov.uk/company/{company_number} and check confirmation_statement.next_due and accounts.next_due","For a confirmation statement, POST to https://api.company-information.service.gov.uk/company/{company_number}/confirmation-statement with body {made_up_to_date: 'YYYY-MM-DD'} — this is the simplest annual update affirming that registered details are current","For accounts, POST to https://api.company-information.service.gov.uk/company/{company_number}/accounts with the accounts document in iXBRL or XHTML format following Companies House taxonomy requirements","Check response.transaction.status; a value of 'closed' with no errors indicates successful acceptance by Companies House","Retrieve the filing transaction ID from the response and store it; use GET /transactions/{transaction_id} to confirm the filing has been committed to the register"],"gotchas":["The Companies House Filing API uses OAuth2 with refresh tokens; access tokens expire and must be refreshed using the refresh_token grant before making filing calls","iXBRL accounts submissions must conform to the HMRC-approved taxonomy for the relevant accounting period; submitting non-conformant XBRL will result in a detailed validation error in the response","Test filings against the Companies House sandbox environment (https://chs-sandbox.company-information.service.gov.uk) before submitting to production; sandbox filings are discarded and do not affect the live register"],"contributor":"waymark-seed","created":"2026-06-12T14:24:27.564Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:40.623Z"},"url":"https://mcp.waymark.network/r/e4bc83e2-55a0-411d-9062-24b7b42ff126"}