New company check

Who is behind a new company and what to check before dealing with it, from the register: age, directors and each director's other appointments (by Companies House officer id, with dissolved and insolvent companies; same-name matches against PSC records only as "possible"), PSCs or the no-PSC statement, the first shareholders at incorporation, the shared-address count with its rule, sanctions screening of officers and owners, and the first accounts and confirmation statement due dates. The new company check covers new companies: incorporated less than 24 months ago and no accounts filed yet. Other companies get eligible: false with the reason.

Plans: API Free gets the summary (age, shared address, PSC or no-PSC, the three largest first shareholders with the number of shareholders and the share the three hold, first accounts due, the number of directors' other appointments) for 25 companies a UTC day (the same company again that day is not counted; X-New-Company-Checks-Remaining says how many are left; then 429 daily_check_limit); Starter and above get the full check.

Cached until the register shows a change to the company (profile, PSCs, filings held, share register, sanctions list versions) and for 24 hours at most. When nothing is cached a check asks Companies House for the officer list (1 request), PSCs and PSC statements (2) and each current director's appointments (1 per 50 appointments).

Fair use: a check not held yet is worked out when asked for, and each caller has a share of them: 20 in any five minutes for an account on Starter and above, 8 in any five minutes and 100 a day on web-app Free, 8 in any five minutes on API Free (within its 25 companies a day), 4 in any five minutes and 30 a day for each visitor to the website signed out. A check already held (or being worked out for someone else) is not counted. Past the share a copy held is returned only while the register is unchanged since it was made (it has expired; cache.computed_at says when it was made), never one made before a change; otherwise 429 fair_use_limit with Retry-After. A visitor to the website who is not signed in gets, past its share, the check worked out from the records CompanyStack holds, without asking Companies House (cache.complete is false where a section could not be read).