Uber’s website explains that, “Being Uber means there is no need to tip drivers with any of our services.”

But as a recent petition explains, this isn’t exactly true. Uber fares include a default 20% tip if you’re taking uberTAXI, but the tip isn’t included if you’re taking an UberX (the lower cost option), UberBlack (the premium option) or UberSUV.

Peter Faris, who has been an Uber driver in DC for over two years, believes all drivers deserve a potential tip, so he created a petition targeting the company’s CEO, Travis Kalanick. “Often, passengers tell me they'd like to provide a tip. But if they don't have cash, they can't do so through the Uber app…Tipping is a surefire way to extend goodwill toward your driver. It's a gesture of appreciation for a job well done, and there's no reason to deny drivers and passengers this option,” wrote Faris.

It’s important to point out that many people find Uber alluring precisely because it doesn’t require cash. It’s also important to keep in mind that many customers, presumably, believe that Uber drivers are automatically tipped, regardless of which service they’re using, as a result of the company’s rhetoric.

Uber has claimed that UberX drivers make between $75,000 to $90,000 a year, which might prompt some to wonder why they need tips. However, independent investigations have suggested drivers not only make a lot less, but frequently have trouble generating something resembling a living wage. Some drivers reported that they are making only $5 an hour.

Faris’ petition received over 13,000 signatures, although it remains unclear whether it will have any impact on Uber’s practices. Regardless, debates about the company’s tipping policy have already introduced another element to Uber’s growing collection of labor disputes. If many drivers rely on Uber as their primary source of income, why can’t customers at least have the option of digitally tipping?