Walmart announced Friday that some of its stores and Sam's Club locations will add tap-to-pay options in the U.S. beginning Monday.Why it matters: The tap-to-pay option has eluded Walmart customers, who have had to rely on the company's Walmart Pay system, which required scanning QR codes at checkout.What they're saying: "We want customers and members to have choice in how they pay, so they can check out in the way that works best for them," Walmart said in a press release."It all comes back to giving customers and members more choice and making everyday shopping a little easier — from how they manage their money to how they pay at checkout."Editor's note: This is a breaking news story and will be updated.