You now have the option at the Starbucks drive-thru to BYOC — bring your own cup

• Starbucks says you can bring your personal cup through the drive-thru now.
• Customers can also choose the "Personal Cup" option when ordering through the app.
• But, there's a limit to how much beverage they'll pour in your cup.

Starbucks is officially now BYOC optional — bring your own cup.

You can still show up empty-handed and Starbucks will give you your drink in its traditional cup. But the coffee giant announced Wednesday that US and Canada-based customers can bring their own clean, personal cups when ordering in the drive-thru and on the Starbucks app.

Previously, the option was only available in-store, but it's expanding as part of a larger push by Starbucks to reduce its waste by 50% by 2030.

The cup doesn't have to be Starbucks-branded. It can be any cup, but you can only order the standard tall, grande, and venti sizes. So, no, they won't fill your 40-ounce tumbler to the brim with iced coffee.

Starbucks app users can now select the "Personal Cup" option when they order their favorite beverage from the chain. Participation at licensed Starbucks locations may vary.

"Offering customers more options to use a personal cup when they visit Starbucks marks tangible progress towards the future," Michael Kobori, Starbucks chief sustainability officer, said. "We know our customers are passionate about the planet, and now, they can join us in our efforts to give more than we take, no matter how they order." 

Customers earn twice as many loyalty points when they pay through the app using a digital Starbucks card.

The app and digital card system has also drawn some criticism. A recent Washington Consumer Protection Coalition complaint accused the company of putting consumers in a "Catch-22" that "traps customers in a cycle." The Coalition alleged that the incremental reloading and tipping options led to customers adding more money to their Starbucks cards than necessary.

Starbucks defended the program and app in a statement to Fast Company at the time, saying customers liked the convenience and that it was committed to ensuring it operated in a way that complied with state laws and regulations.

But those who prefer to double up on points through the app can now do so sustainably — with their comfort coffee mug.