Skip to content

Migration FAQ

Last updated: April 29, 2022

Below you'll find the answers to some of the most frequently asked questions about migration from the Classic API to the Unified Payments API.

Can I perform refunds through the Unified Payments solution on payments created using the Classic API?

Yes you can. To do so, you can call the /refunds endpoint in the Unified Payments API with the charge ID of the capture. For example:


"reference": "ORD-5023-4E89"

If you rely on webhooks, you will need to maintain your Classic API webhook handler for the above scenario only. This is because in the above scenario, we will send you Classic API event types.

Can I use my existing public and secret keys in the Unified Payments API?

Yes you can.

Can I use both the Classic API and the Unified Payments API at the same time?

Yes you can. The webhook event types that you will receive are governed by the Gateway API used to request the payment. This means that if you request a payment using the Unified Payments API, you will receive only its associated webhook event types.

Can I process alternative payments through the Checkout.js solution?

No, Checkout.js is now deprecated. You should upgrade to our Hosted Payments Page or Frames. You can also read our full Checkout.js migration guide.

Can the Classic API and Unified Payments API webhook event types be used simultaneously?

Yes, this setup can be configured in particular situations. Please email for more details.

Can I use a charge ID in the previous_payment_id field for recurring payments in the Unified Payments API?

Yes you can. The previous_payment_id field supports payment IDs, charge IDs, as well as scheme IDs.