Implement Wise Platform relayed authorisation to approve or decline card transactions in real time on Wise-issued cards

Steps

1. Confirm relayed authorisation is enabled for your card program (added to Wise Platform card issuance in the March 2026 changelog) before building a real-time decisioning endpoint
2. Stand up an endpoint that receives the relayed authorisation request at the moment of card transaction authorization, not after the fact
3. Apply your own approve/decline business logic (velocity, MCC, merchant, balance checks) synchronously within Wise's response-time window
4. Read the relayed authorisation data now included on the card transaction API and the cards#transaction-state-change webhook to reconcile the final decision with your ledger
5. Fall back to a safe default (typically decline) if your endpoint times out or errors, so a downstream outage doesn't silently approve unauthorized spend