Pre Authorization

Reserve a fixed amount on a payment mean.

• The amount you want to debit may be lower than the reserved amount, but not higher
• Chargingthe pre authorisation works with certainty
• Pre Authorizations last around 5 days (this duration depends on the issuer)

Process

Gateway Creation

Pre-authorizations can easily be implemented using the zahls.ch Gateway.
Use the parameter reservation to do so.

Build Your Gateway→

Customer Authorization

This step is identical to the "payment" step in the Gateway documentation.
With a pre-authorization, the only difference is that the amount is not debited but reserved.

Also a transaction webhook with the transaction status reserved will be triggered.

Charge Reserved Amount

Get Transaction ID

The transaction ID is present in the transaction Webhook.

You can find this ID also if you retrieve a Gateway through the zahls.ch API.
Small hint on where to find the transaction ID in the retrieve a Gateway respone:

{
    "status": "success",
    "data": [
        {
            "id": 1,
            "status": "reserved",
            "invoices": [
                {
                    "transactions": [
                        {
                            "id": 2012844,
                        }
                    ],
                }
            ],
        }
    ]
}

Execute Charge

Use Charge a Pre-Authorized/Reserved Transaction to make a charge on the reserved transaction. You will need the ID of the transaction with status "reserved" to do so!