Authorize.net does not allow settling transactions for more than the original amount.
We do, however, have an option available that authorizes a hidden surcharge.
It's a feature which is used together with Authorize.net and delayed capture. Since Authorize.net doesn't allow to increase the order amount with delayed capture, this feature accommodates it by adding a surcharge so you can adjust the pricing however you would like on an order.
The user is not aware of the surcharge e.g basket, checkout, order conf, order history, etc.
When the order arrives on the POS you can make the appropriate adjustment to capture the correct/final amount.
NOTE: it requires enabled Delayed Capture
How to Enable
It is set up on the Payment Plugin Configuration page. The option is called:
✔Add a hidden authorization surcharge to transactions (requires WSM configuration option 'Set Hidden Authorization Surcharge % for supported payment plugins' and Delayed Capture)
This option lets you set the percentage of the order total that is additionally preauthorized on each transaction with supported payment plugins. Enter the amount as a percentage, e.g 25 = 125% of the order total will be authorized. Requires Delayed Capture and other corresponding options to be enabled in the payment processor configuration panel.