Check a structured ISO 20022 postal address against a payment rail's published address rules, rule by rule, each verdict citing the document it comes from. USE WHEN: assembling a payment instruction (pain.001, a Fedwire message, a T2 transfer) with a creditor or debtor address, to learn whether the rail accepts it BEFORE submitting. The November 2026 changes (SIC 20.11, Fedwire 16.11, T2 R2026.NOV) remove the fully unstructured address option — this check tells you whether an address survives them. DO NOT USE to verify that a street or town EXISTS: this checks conformity with the message format rules, not postal reality. SCHEMES: 'sps' (Swiss Payment Standards, SIX), 'hvps_plus' (HVPS+ / T2, ECB), 'fedwire' (Federal Reserve). There is deliberately NO 'cbpr+' scheme: that guideline sits behind swift.com, unreachable to automated readers, and a conformity boolean quoting an unread document would be a guess dressed as a verdict — the note field restates this on every answer. VERDICTS: pass, fail, and not_applicable — the last marks a rule whose precondition is not met and never counts as a pass. conforms is true when no finding failed. IMPORTANT: relay each finding's source string — it names the exact document, version and validity date the rule is quoted from. They are what makes the verdict auditable. FREE: the rules are published commodities. The paid surface is the postal_address block that /v1/bic and /v1/iban/validate return for the resolved institution. COST: $0 per call, on every surface (free with no key on this transport: 25 units a week per source address, one per call and one per IBAN in batch_validate_iban, reset on Monday 00:00 UTC. Or an ifk_ key with no e-mail at all: POST https://api.ibanforge.com/v1/keys/generate with no body for 25 REST calls/month, and POST /v1/keys/claim lifts that same key to 200 a month).