Amounts and Reversals and Voids. Oh, my.

With our upcoming installation (fingers crossed) of Flexible Spending Account (‘FSA’) functionality at one of our OLS.Switch client sites, we’ve implemented a new tranlog column called ‘originalAmount’.  FSA is joined at the hip to partial authorization and real-time credit reversals.  We’ve implemented partial auth before for our Stored Value Systems (‘SVS’) interfaces, but we were more ad-hoc about that.  Now, with the advent of FSA and the overall partial auth focus in the payment switch industry, we’re taking a more permanent approach on this thing.

I summarized the key points to our flagship client like this:

1. The originalAmount column will always get populated with the incoming <amount> field from the incoming store request – this is true for all financial applications (Debit, EBT, all Credit, all SVC and Check)
2. For all financial requests except sales/purchases authorized by Stored Value Systems (‘SVS’) and FSA transaction originals (i.e., not reversals) authorized through FDR North, partial auths are not in play.  The incoming <amount> field is also placed into the amount column. 
3. For SVS-authorized sales/purchase requests and FSA sales/purchase requests authorized by FDR North, partial auths are in play.  The amount authorized – as returned from the endpoint in the ISO8583 response – is placed into the amount column. [NOTE:  Though we support SVS partial auths today, we currently retain no evidence of the original request amount on the tranlog.]
4. For FSA voids, the incoming <amount> on the store’s request reflects the authorized amount of the corresponding original.  To be safe, we pluck the amount to reverse from the amount column of the corresponding original and use that to populate the reversal.  Unlike ‘basic’ credit, FSA terminal voids and reversals must be sent to FDR North via Store and Forward (‘SAF’) processing.
5. For FSA timeout reversals (at the terminal), the device is not aware of any partial auth that might have occurred, so the incoming reversal request has the amount originally requested.  That’s what ends up in the originalAmount column of the reversal.  The amount column of the reversal will contain the amount we pluck from the same column in the corresponding original.
6. The FDR North switch interface does not support Host timeout reversals of Credit (which includes FSA).
7. SVS voids and terminal timeout reversals are not implemented by the store system.
8. The SVS switch interface does support Host timeout reversals.