Limit splitting by payment method

Some payment integrations assume that one checkout produces one Magento order and one external transaction. Use the allowlist to restrict Order Split to methods you have tested.

An empty allowlist permits every payment method. Once at least one method is selected, another method follows Behavior for Disallowed Payment Method:

• Block Checkout stops submission with an explanatory error.
• Create Single Order skips splitting and submits the original quote.

The extension also validates the chosen payment method against every split quote immediately before order creation. If it is not available or fails validation for one group, the same block or single-order behavior applies.

The checkout notice only hides the warning when the chosen payment method is on the allowlist — it does not make an incompatible payment method safe. Test authorisation, capture, cancellation, invoicing and refunds for every allowed integration.