“Checkouts are failing” warning
Paddle refused to start a checkout because your Paddle account itself needs a setting. The warning says which one:
- No default payment link: in Paddle go to Checkout → Checkout configuration and set Default payment link to your checkout page.
- Website not approved: in Paddle go to Settings → Website approval and add your domain.
The warning disappears after the next successful checkout.
“Something went wrong starting the payment” at checkout
Paddle refused to create the checkout. Open the order: the note “Paddle checkout could not be started: …” shows Paddle’s exact error. Common causes are a missing default payment link or website approval (Billing), or two subscription products in one order.
Paddle’s own checkout shows an error
Billing: make sure your domain is approved in Settings → Website approval and the client-side token belongs to the same environment (sandbox test_…, live live_…).
Paddle does not appear at checkout
- Enable Paddle is not ticked.
- The credentials for the current mode are missing, or the client-side token has the wrong prefix. Check the Sandbox setting, then the matching Live or Sandbox fields.
- Your store currency is not supported by Paddle. See Taxes and currencies.
- Paddle Classic only: the cart holds a subscription and your store currency is not USD, EUR or GBP.