Do not point your integration at production on day one. Prove it out on the dev environment first, with a throwaway legal entity, and only onboard the real one once you have watched real test payments succeed end to end.
Step 1: Onboard a dummy legal entity on dev
On https://midlayer-dev.woosa.nl, walk through Part 5 with a test legal entity: made-up (but validly formatted) company details, a test contractor, and a test store. Complete onboarding (Part 5d) for this dummy entity so the store is actually able to take payments — Adyen's test environment will accept it without real KYC documents.
This dummy entity's only job is to let you exercise the full flow without touching anything real. Do not reuse it once you go live.
Step 2: Run test payments
With the dummy entity's store, work through the core loop in Part 7 and Part 8 using Adyen's test card numbers and test iDEAL/redirect flows. At minimum, confirm your integration correctly handles:
A straightforward payment that authorises immediately, with no extra shopper step.
A payment that requires a redirect or challenge, including the return to payment-details (Part 7c).
A capture, whether automatic or manual, depending on how your store is configured.
A full refund and a partial refund.
A cancel on a payment that has not yet been captured.
Polling updated-payments and correctly matching results back to your own orders using metadata.
A failed or declined payment, so you know your shop handles that gracefully too.
Only move on once every one of these behaves the way your shop expects, and your order statuses update correctly in each case.
Step 3: Onboard the live legal entity
Once the dev tests are clean, repeat Part 5 against production (https://midlayer.woosa.nl), this time with the merchant's real legal entity, real contractor details, and real store. This is the entity that goes through genuine KYC — the merchant will need to provide real identity and business documents during onboarding (Part 5d).
Remember: production has its own registration (Part 2) and its own woosa_secret. Dev and production are entirely separate merchant accounts with separate credentials — a dev secret will not sign valid requests against production, and vice versa.
Step 4: Switch over
Point your shop's base URL at https://midlayer.woosa.nl.
Confirm you are signing with the production woosa_secret, not the dev one.
Re-check onboarding-status (Part 5d) for the live legal entity to make sure it is fully verified before you rely on it.
Re-enable the payment methods you want live (Part 6b) — method configuration does not carry over from dev to production.
Run one small real payment yourself first, end to end, before opening the doors to real customers.
Go-live checklist, in one line: dummy legal entity on dev → full test-payment run-through → real legal entity onboarded on production → switch the base URL and secret → one real test payment → live.