While passengers have the option of giving their driver money as a thank you, the Uber model runs as a cashless economy – part of the reason it’s so popular. Many clients don’t have cash on them, nor do drivers have the ability to make change if the client does want to give them a tip.

That’s the reason Uber’s biggest competitor, Lyft, gives users the option to leave a tip via their app. But Uber refuses to do the same, and they say it’s because of racism.

A spokesperson for Uber told the Boston Globe that studies show riders have a racial bias toward white drivers and minorities will come out short changed (pardon the pun) if tipping is involved. Therefore, they discourage tipping to ensure drivers are fairly compensated, and that is why the website tells users that there is no need to tip. Unfortunately, many riders have misinterpreted that to mean the tip is included, when drivers only receive the fare, minus the 20-25% that goes to Uber.

The ride sharing company recently settled a $100 million class-action lawsuit, and although they can still call drivers independent contractors instead of employees (therefore denying them insurance and paid time off), drivers were given more rights than before, like the right to inform passengers that tips are not included in the fare. But that falls solely on the driver, not the company. Uber stands by their decision to not include tipping on their app.

Lyft, however, has had no issues where tipping is concerned. A spokeswoman for the company told the Globe that riders are not only happy to give tips, they have been generous with their money.

“Lyft has had tipping since the beginning. We wanted passengers to have a way to show their appreciation to drivers who go above and beyond to give a great ride or be extra helpful, since so many of them do.”

Lyft drivers have so far received more than $85 million in tips combined.