Implement Auth/Complete payment

Auth/Complete allows you to verify the card for a payment ("Yes, card validates and has credit to buy your widget"), then delay the transaction until confirmed by the merchange ("but do we have any widgets in stock?"). This helps the merchant avoid chargeback fees when stock levels are not certain or in other cases where you may want to confirm the transaction before accepting it.

From http://www.paymentexpress.com/technical_resources/ecommerce_nonhosted/px...

Payment Express supports Auth/Completion. An "Auth" transaction verifies that funds are available for the requested card and amount and reserves the specified amount. A "Completion" transaction is sent at a later date to cause funds transfer for the previously authorised amount, or a smaller amount if the total original value is no longer required. This transaction set is useful when the merchant needs to ensure that funds up to a certain limit are available but the actual total amount is not yet known or goods or services have not yet been delivered.

This functionality is only available in PXPost, not PXAccess.