API handles the calls for starting and completing the transaction in one go. The merchant calls this API with the same parameters as the Transaction Start V16 with the necessary card data appended to it. For existing transactions the orderId and entranceCode can be passed on instead of the transaction details.

Note: this API can only handle:

1. NON 3DS transactions - no fallback to 3DS auth
2. 3DS transactions where the merchant provides the 3DS data (using 3rd party 3DSecure provider)
3. 3DS transactions where the merchant adds the transaction ID of the integrated 3DSecure provider
4. Wallet transactions (e.g. Apple Pay / Google Pay)