POST /v1/subscriptions/{subscriptionId}/billing-rail

Authentication

Send an API key as a bearer token. The key must carry the billing.payment.manage permission; a key without it is refused with 403, not 404.

This endpoint takes no organisation id. Your key already identifies the organisation it belongs to, and the response is scoped to it.

Try it

Replace anything in angle brackets with your own values, and the key placeholder with a key from your dashboard.

curl -X POST https://api.zinndigital.com/v1/subscriptions/{subscriptionId}/billing-rail \
  -H "Authorization: Bearer zdk_live_…" \
  -H "Content-Type: application/json" \
  -d '{ "rail": <string<engine, paypal>> }'

Signed in? The API console in your dashboard fills in your real organisation id and your own key, and runs the request against the live API so you can see the actual response. Open this endpoint in the API console

Details

Move a subscription between the engine rail (we invoice and charge on the renewal date) and the PayPal rail (PayPal charges on its own schedule under an agreement the customer approved). ADR 0029 records the boundary: PayPal owns only when the money is taken — the engine still owns what is owed, tax, entitlements, dunning and suspension. ⛔⛔ Switching to PayPal returns an approval_url and grants nothing. Until the buyer approves in PayPal's own interface and PayPal sends us a signed BILLING.SUBSCRIPTION.ACTIVATED webhook, the agreement cannot charge and the subscription's clock has not started. active is false for exactly that reason. The browser's return from the approval URL is an attacker-supplied claim and is never treated as approval. Switching away cancels the agreement at PayPal first and unbinds second. The reverse order would hand the subscription back to the engine's renewal sweep while PayPal was still entitled to charge it — a double charge for the window between the two calls. Requires billing.payment.manage. 422 carries a code: ALREADY_ON_RAIL, NO_CATALOGUE_PRICE, PRICE_WOULD_CHANGE (the subscription is on a price that differs from the published one, so switching would change what the customer pays — refused rather than done quietly), NOT_SWITCHABLE, or PAYPAL_REFUSED.

Parameters

Request body

Response

Errors this endpoint can return

401 · 403 · 404 · 422 · 429