While retailers across the country installing chip-and-PIN card readers to better protect consumers’ bank information during checkout, Walmart claims in a recently filed lawsuit that Visa is urging the retailer to use a less-secure method for verifying debit card payments. 

Walmart filed the lawsuit in a New York state court on Tuesday claiming that Visa is trying to prohibit the retailer’s ability to route any transaction initiated on a Visa-branded debit card though any available network.

According to the redacted complaint [PDF], Walmart accuses Visa of suggesting it verify transactions made with certain debit cards with signatures rather than a PIN in order to route the transactions through its own networks.

“The parties’ dispute exists because Walmart implemented a ‘chip-and-PIN’ protocol for debit card transactions: when consumers presented a debit card with an embedded computer chip for payment, Walmart required consumers to insert their card into a terminal that could read the computer chip and then required consumer to enter a Personal Identification Number to verify their identities,” the complaint states.

Walmart contends that PIN verification is “much more secure than signature verification.”

However, Visa believes that Walmart should be required to use the more “fraud-prone system of signature verification,” the retailer says in its complaint. These transactions would then be routed across Visa’s debit network rather than competitor networks of Walmart’s choice.

It’s unclear what Walmart seeks with the lawsuit, as the relief statement has been partially redacted. But it might be reasonable to assume it seeks to ensure PIN verification is the transaction of choice and that it can use other network systems.

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