Authorization

When submitting a charge it is important to send in the correct intent and to take into account the differences in authorizations:

Final authorization
Pre-authorization
Incremental authorization

Final Authorization

A final authorization is sent by setting purchase as intent in the charge type. This is used when the amount is known and fixed prior to sending in the charge request for authorization. This means the amount can no longer be adjusted after authorization and the charge is expected to be cleared according to the Card Network rules (Mastercard: 3 days, Visa: 7 days).

Pre-Authorization

Pre-authorization is selected by using reservation as intent when creating a charge. This is used when authorization is requested for an estimated amount and the authorization is expected to be adjusted or the transaction is not expected to be cleared within a prescribed number of calendar days. The clearing window for pre-authorization is often much longer. Example scenarios are:

An e-commerce merchant would like to obtain an authorization for an item which might take more than 7 calendar days for it to be available in stock.
A travel or hotel merchant would like to obtain an authorization for a charge where the final amount will likely still be adjusted prior to the charge being submitted for clearing.

Incremental Authorization

Incremental authorization does not replace the original pre-authorization, it is additional to the previous authorized amount. An incremental authorization is sent by referencing the charge key from the original pre-authorization, and will only be possible if the reference charge has not been cleared. Multiple incremental authorizations can be performed. For that, you use the Increment endpoint and only send in the replacement amount which should become the new authorization amount. If the final amount is lower than the amount estimated in the Pre-Authorization charge, a reversal must be sent with the difference and the final amount is cleared. The validity of an incremental authorization is similar to that of a Pre-Authorization, please see the table for more information.

Authorization Validity

Type	Mastercard	Visa
Final authorization	7 days	7 Days - CNP 1 day - CP
Pre-authorization	30 days	31 days - Lodging, Vehicle Rental, Cruise Lines 7 days - CNP, Transportation & Rental merchants (in the U.S. 3 days) 1 day - CP

An example scenario: A hotel merchant would like to send an incremental authorization after the initial Pre-Authorization, when a client has used additional paid services.

Address Verification Service

The Address Verification Service (AVS) is a functionality provided by card networks and issuers to merchants in order to detect suspicious credit card transactions and prevent credit card fraud.

Silverflow offers Address Verification Services (AVS) functionality on the platform. AVS is a tool that allows merchants and acquirers, especially those operating in an e-commerce environment, to compare various subfields such as postal code, name, address, email and phone number provided by the customer at the point of sale with cardholder information on file with the issuer. When used correctly, AVS can lead to a signification improvement in authorization rate, and is commonly used in the US, the UK and Canada.

AVS with Silverflow is supported for Visa and Mastercard transactions. Card issuers in the United States, Canada, and the United Kingdom must support AVS verification requests when submitted, however, using AVS is not mandatory for acquirers.

How to Use AVS with Silverflow

Ensure you are collecting the cardholder's billing address as part of the checkout process.
When calling the POST/charges endpoint as part of the authorization flow, ensure that optional field avs:true
When avs:true, billingAddress is required
Silverflow will include this information in the authorization request passed to the issuer, which then compares these details to the address they have on record for the cardholder.

AVS Example Request

AVS Response
Silverflow will provide the direct card network AVS result code back to the agent in the charge response under authorizationIsoFields in the avsResponse field for Mastercard or the avsResultCode field for Visa trnasactions.

Visa AVS Response Codes

Y	AVS full match
A	AVS street address only (partial match)
Z	AVS postal/zip code only (partial match)
N	AVS non-match
R	AVS indeterminate outcome (retry)
U	AVS unable to verify

Mastercard AVS Response Codes

A	Address matches, postal code does not
N	Neither address nor postal code matches
M	Street addresses and postal code match
R	Retry, system unable to process
S	AVS currently not supported
U	No data from issuer/Authorization Platform
W	For U.S. addresses, nine-digit postal code matches, address does not; for address outside the U.S., postal code matches, address does not
X	For U.S. addresses, nine-digit postal code and address matches; for addresses outside the U.S., postal code and address match
Y	For U.S. addresses, five-digit postal code and address matches
Z	For U.S. addresses, five-digit postal code matches, address does not