Discover Reason Code UA05: Fraud, Chip Counterfeit

What Discover reason code UA05 means

UA05 is Discover’s code for counterfeit chip-card fraud. A fraudster copied the magnetic stripe data from a genuine chip card onto a counterfeit card and used it at a terminal. Because the transaction was processed from the stripe rather than the chip, the chip’s anti-counterfeit protection never came into play.

The EMV liability shift decides who pays. When the genuine card had a chip and the merchant’s terminal couldn’t read it, liability for the counterfeit generally falls on the merchant. When the terminal was chip-capable, the liability generally stays with the issuer.

UA05 rarely applies to ecommerce. It requires a physical card read at a terminal. Online fraud claims come through as UA02. An online store receiving UA05 should ask its processor whether the transaction was flagged as card-present by mistake.

Common causes

• Magstripe-only terminals still in use at some locations
• Chip readers that are broken, so staff swipe instead
• Unattended terminals, such as kiosks and fuel pumps, that haven’t been upgraded
• Chip read failures followed by a swiped “fallback” transaction

Evidence for a UA05 dispute

1. Terminal capability: proof the terminal was chip-capable at the time of the transaction.
2. Entry mode: the transaction record showing a chip read, not a swipe or key entry.
3. Authorization data: the approval code and the chip data your processor recorded.
4. Fallback handling: if the chip couldn’t be read and you swiped as a fallback, the record showing the fallback was flagged and authorized. Fallback rules vary, so check with your processor whether this is a defense.

How to prevent UA05 chargebacks

• Replace any terminal that can’t read chips, including unattended ones.
• Repair faulty chip readers promptly rather than letting staff default to swiping.
• Watch fallback-transaction rates by location. A spike usually means a broken reader or a skimming attempt.

Should you fight or accept?

Fight only when your records show a chip read on a chip-capable terminal.

Accept when the transaction was swiped on a terminal that couldn’t read chips. Under the liability shift that loss is yours, and the real fix is replacing the hardware.