Pre_Auth, Pre_Auth_Competion, and Force_Post Processing

Product   Credit Hub 
Synapse's Sub-category  EXTERNAL-US(PURCHASE)
Use Case Credit Card Processing 

EXTENRAL-US (PURCHASE) is a type of transaction that Synapse is using to identify credit card purchases, those usually involve a vendor and the end user. Synapse is not the authority that processes those transactions but rather subject to Credit Network rules (MasterCard in our case) that Synapse must honor. The Credit Network is structured as a messaging system that transfers information between the vendor and the end user regarding the status of the transaction (i.e request to set a hold on the account, request to settle the transaction, etc). Below you will find information on the 3 types of credit card messages: pre_auth, pre_auth_completion, and force_post.

💳 What is a pre_auth?

  • Pre_auth functioned as a credit network message that initiates a ‘hold’ for a certain amount when a purchase is made.
  • Pre_auth is considered the safest credit transaction as it ensures the user has enough funds by placing a hold on the account, and functions as a guarantee for the vendor to receive the funds.
    • An example of a pre_auth transaction in our daily life is when we are purchasing gas; the hold (for $200) that is first placed on our credit card is essentially the pre_auth. When the transaction is finalized we will see the hold overwrite with the new amount of the transaction (this type of transaction is called pre_auth_completion).

💳 What is a pre_auth_completion?

  • Pre_auth_completion functions as a credit network message that instructs the system to finalize the pre_auth transaction that associates with it.
  • Each pre_auth transaction has a unique identifier and when a pre_auth_completion is sent, Synapse will then map that identifier and overwrite the amount in the pre_auth only to count the amount that is stated in the pre_auth_completion.
    • Going back to our example with gas stations, pre_auth_completions are sent once the amount is finalized, and it is simply a system request to charge the user.
  • Please note that we have to honor pre_auth_completion transactions; any request to cancel those transactions will have to be disputed through our credit partner (you can find more information about this process below)

💳 What is a force_post?

  • In some cases, a transaction will send to us without pre_auth completion - those are called “force_post” transactions.
    • In those situations, we will not place a hold on the account and we will simply charge the user the amount that is stated on the force_post request.
  • As the name suggested, those transactions are “forcing” the user to pay the amount; hence, those transactions are instantly approved without any verification.
    • To emphasize this further, even if a user does not have enough funds, the node is closed, or the account is locked, the transaction will be settled.
  • With that being said, those transactions carry a high risk since no validation can be made and usually indicate fraudulent activity, but not always.
    • An example of a valid force_port transaction can be a subscription; the vendor will usually send a force_post transaction to “force” the user to pay (please see below for more details about force_post and how to handle those better).

💳 What can be done if a force_post has been settled but the user is unauthorized/doesn’t have enough funds?

  • We at Synapse do our best to protect our users and customers, but we are also restricted to credit network rules that we have to respect.
  • Since force_post transactions should be settled regardless of any validation on Synapse’s end, in case the user is unauthorized/doesn’t have enough funds, you will need to apply for a dispute, this is the only way to cancel or return the force_post transaction.
  • More information about how to apply for a dispute can be found in our Card Dispute Guide.

 Additional Information

Pre_auth and pre_auth completion.

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