Reconcile a Norwegian company's Altinn 3 filing history against the filings YOUR consumer submitted through Apier. Given a 9-digit organisasjonsnummer it returns the org's Altinn filing instances (Mva-melding, A-melding, Skattemelding, …) — form code, title, agency, submitted_at (Europe/Oslo), status, instance id — each paired with its Apier audit record where one exists (`filed_via_apier` + `apier_record`). Offset-paginated via { limit } (1–100, default 20) and { offset }; no filings → 200 with an empty list, never a 404. MOCK-GATED until the `altinn:instances.read` Maskinporten scope is approved. Failure modes: SCOPE_INSUFFICIENT (needs read:altinn), AUTH_NO_DELEGATION (live mode), VALIDATION_FAILED. For upcoming deadlines rather than past filings, use get_company_deadlines instead. No API key? Bearer apier_sandbox_test_<suffix> (fresh suffix) serves synthetic fixtures; org numbers: GET /api/v1/sandbox/fixtures. Cost: 50 øre (NOK 0.50) per call, prepaid (prices: the get_pricing tool or GET /api/v1/pricing; a shortfall returns INSUFFICIENT_CREDITS with top_up_url). Docs: https://www.apier.no/docs/guides/audit-inspection