Preview the accounting period from Companies House
https://app.speybooks.com/api/v1/organisation/accounting-period/previewPreview the accounting period for a Companies House number without writing anything. This is the read side of the confirm step: it returns the looked-up identity and registered office for the user to confirm against, alongside the derived accounting period, so a valid but wrong number (one that passes the format check and resolves to a real but different company) is caught before anything is set.
The settable flag reports whether the period can still be set: true only while no activity has been recorded, the same condition the set endpoint enforces before it writes. When settable is false the organisation has posted activity and the period is fixed, so the confirm action should not be offered.
Companies House failures mirror the set endpoint: company_not_found (404), company_not_active (422), companies_house_unavailable (503), and invalid_company_number (400) for a malformed number that never reaches Companies House.
Body parameters
companyNumberstringrequiredResponse
Show response fields
accountingReferenceDateobjectShow child attributes
dayintegermonthintegercompanyNamestringcompanyNumberstringcompanyStatusstringentityTypestringincorporationDatestringperiodobjectShow child attributes
yearEndstringyearStartstringperiodSourcestringregisteredOfficeobjectShow child attributes
addressLine1stringcountrystringlocalitystringpostalCodestringsettablebooleantypestring