UPDATE, 3:55 pm: Uber spokeswoman Kate Downen tells WW the company has finished its city paperwork and will begin running cars at 2 pm Friday.

ORIGINAL POST, 2:58 pm: When Portland City Council legalized Uber on Tuesday, it added a significant new piece of regulation to keep an eye on its drivers.

City Commissioner Dan Saltzman added a last-second amendment requiring Uber to confirm its drivers have obtained a city business license before letting them use the app.

That's important because it means Uber's drivers can't use the platform unless they're being tracked by city regulators—a major contrast to lax requirements for Airbnb operators, most of whom have still not applied for a city permit.

A notice sent by Uber to its drivers today shows the company is rushing to comply with the new rule.

The email, obtained by WW, shows Uber telling its drivers they must get a Portland business license by noon Friday if they want access to the app. (Registering for a city business license is free.)

"Failure to comply with these requirements by 12 noon on Friday 4/24 will result in temporary deactivation of your account," the email says, "until the requirements are met."

While the Uber email does not tell drivers when the service will launch in Portland, it shows the company is trying to meet all city rules by noon tomorrow.

It also tells drivers to prepare for the two Trail Blazers playoff games at the Moda Center—on Saturday and Monday—strongly implying the company expects to be running cars by then.

Uber's main competitor, Lyft, has announced its plans to launch in Portland at 2 pm tomorrow.

Here's a portion of the Uber email to drivers, sent this morning shortly before 10 am: