There are situations when it may appear that a debit card has duplicate charges when in fact there is only one charge.  The “duplicate” charge is not an actual charge but a “pending charge” or “authorization.”  This occurs as a result of an attempt to complete a transaction that has been declined.  Understanding why this can occur requires a little understanding of how payment processing works.

For a credit or debit card transaction Doubleknot verifies the following information:

• The available credit,
• The street address,
• The code zip code, and
• The three or four digit card security code.

In credit and debit card payment processing, the street address, zip code and security code verification are optional and left to the discretion of the merchant or, in this case, Doubleknot’s discretion.  There a number of reasons why it is the merchant’s discretion but it is primarily due to the fact that:

• Most merchants do not require this information for “card present” transactions meaning the cardholder and card are physically present for signature and/or identification checking,  and
• Across the globe not all banks support this additional level of verification.

As such, if there is available credit or funds in the account the transaction is approved by the bank regardless of whether or not there was positive verification of the street address, zip code and security code.  However, along with the approval code the results of the street address, zip code and security code verification are returned.

When a transaction is approved and either the street address, zip code or security code verification fail, Doubleknot will decline the transaction.  Doubleknot will send a message back to the bank to void the transaction.  Sometimes the voids are not processed as quickly and the “pending charge” remains for a day or two before it disappears.