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This FAQ is comprehensive to WEX Chip and WEX Spec 4.1.4 questions.

Compliance dates are listed below. WEX is targeting Q3 of 2020 to begin Chip card issuance.

WEX Chip Card
Compliance Release 2 – October 1, 2020
Compliance Release 1 – January 1, 2020


WEX Chip Card

Will there still be a magnetic stripe on the card?

Yes, there will be both a magnetic stripe and a chip on the new cards. The mag stripe will be used by those merchants and POS systems that do not yet accept the chip.

What are the benefits of switching to chip?

Chip cards prevent white plastic or fake card counterfeiting, which benefits the fleet driver, manager, WEX, and accepting merchants.

Are there any mag stripe features that will be lost while using chip?

No, switching to WEX Chip doesn’t remove any existing features.

Why is WEX switching to chip?

WEX is switching to chip cards to give our customers enhanced security and additional features and functionality.



Will the sales file change with EMV?

There are no format changes to the sales file specification; there are additional values added to the sales file to designate chip card transactions.

What chargeback reason code will be used for EMV transactions?

WEX has repurposed chargeback reason code 10 to indicate EMV chargebacks.


Compliance Release 2

October 1, 2020

Do you have terminal action codes?

The terminal action codes are in Table 122 of the 4.1.4 spec (Section 8.6).

Do you have public working keys?

WEX’s public keys are available below:

What is limiting product dispensed (unleaded vs. diesel) on preauthorization response?

The POS and network must support DE62 (Available Products) for a minimum of the fuel fields. WEX will return a fuel product group code. (Section 5.6.22 of the WEX Spec)

What is WEX BIN 707138?

This is not a new BIN, it has been included since the iSpec 2.0, but this is the first time there is a compliance date associated with it. It is defined to match the current BIN 690046.

Does WEX allow fallback to mag stripe at the Automated Fuel Dispenser?

Fallback at the pump may depend on a merchant’s (or their vendor’s) chip implementation at the site – both at the pump and inside the store:

  • Inside – If the WEX chip card cannot be read, the transaction may fall back to magstripe.
  • Outside – The customer experience may vary depending on how the site wants to handle fallback. The WEX chip card may fallback to magstripe at the pump or drivers may be directed to see the Cashier inside if the chip card cannot be read at the pump.

Does WEX still require supporting blocking a chip?

No, this has been taken out of scope.

What does it mean to support purchase device sequence number (PDSN)?

WEX’s requirement is that the merchants use Tag DF39 or Tag 57 (Track 2 Equivalent) to get the PDSN. (Section 3.1.4 of the WEX Spec)

Does WEX require supporting prompting for EMV Chip?

WEX’s requirement is that the merchants use the Tag DF30 or Tag 57 (Track 2 Equivalent) to get the prompting information. (Section 3.1.4 of the WEX Spec)

What are chip based offline purchase restrictions?

When the merchant cannot reach the WEX host, chip transactions are limited to the purchase restrictions on DF32 or Tag 57 (track 2 equivalent) which can also be used for the offline purchase restrictions. (Section 3.1.4 of the WEX Spec)

Where is the WEX technology indicator?

WEX does not use the service code as other major brands do. The WEX technology indicator is in position 33 of Track 2.

What is the user experience when a WEX Chip card is used at an EMV enabled site that doesn’t recognize WEX Chip?

The site should recognize that the AID is unknown, the BIN is recognized as not on chip yet, so the transaction is processed using the magnetic stripe. This aligns with the best practices recommended by the US Payments Forum.

Are there changes needed to the kernel to accept the WEX Chip?

No, WEX is using the PURE applet and no changes are required to the kernel for acceptance. Note that some kernels do need updates to read the DF30-DF39 tags, therefore, WEX supports Track 2 Equivalent (Tag 57) so that chip transactions can be processed until those kernels support the chip DF tags.


Compliance Release 1

January 1, 2019

What is Card-based Flexible Prompting?

Card-based flexible prompting, as described in WEX Spec (Section 3.1.1), is also referred to as "Enhanced Prompting". It includes any prompt combinations read from the magnetic stripe.

What are Real-time Sales Completions?

Real-time sales completions refer to WEX receiving the completion message of the sale at the time the driver hangs up the nozzle. (Section of the WEX Spec)

What are offline Card-based Purchase Restrictions?

WEX requires merchants to send purchase authorizations to WEX for approval/decline. However, when the merchant cannot connect to the WEX host, the merchant should use the purchase restrictions on the card to determine if the products are permitted for purchase.

The terminal should not add products between the preauthorization and completion (the exception is car wash). If WEX hasn’t authorized it, it should not be sold. (This changes if the POS supports DE 62 Available Products in which case they can add items following the processing rules of Available Products.)

If the terminal supports store and forward and is processing a transaction when it cannot reach WEX, then it should limit the items purchased as follows:

  • Magstripe is limited to the two digit purchase restriction on the magstripe (Sections 3.1.1 and 3.1.4 of the WEX Spec)
What is Dollar Shut-off?

Dollar Shut-off is also called "Partial Authorization". WEX may return an amount greater than, equal to, or less than the amount requested. A merchant site may lower the amount WEX returns based on local requirements. (Section 4.5.4 of the WEX Spec)

What are Real-time Sales Transactions?

Sales must be done in real time (1200 messages must come up for authorization).


Last Updated: June 2020