Starbucks is ready to shake up its rewards program next month by adding a new way to get extra stars.

But the benefit won’t necessarily apply to every customer who walks through the door.

How Do Starbucks Rewards Work?

The coffee chain has a long history of operating its Rewards program. Members of the free program have an opportunity to collect stars with every purchase.

How those stars are awarded varies according to how the customer is paying.

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According to Starbucks’ terms of use for Rewards, customers can earn two stars for every $1 spent when paying with a Starbucks Card. The reward amount for customers paying with cash or a credit or debit card is one star for every $1 spent.

Stars can be traded in for something as small as a free drink customization (25 stars) or as large as Starbucks merchandise (400 stars).

How Starbucks Rewards Is Changing

Starbucks sent a notice to all Rewards members on May 26, notifying them of potential updates to the program’s terms of use that will take effect on June 24.

“Members who use their own personal cup will now earn Double Stars on their entire order,” the email informed Rewards members.

Customers are asked to bring in clean, reusable cups that will be used for their order instead of the chain’s paper cups. Both in-store and drive-thru customers can use the benefit.

Starbucks’ Reusable Cup Benefit can be redeemed up to three times each day and once per order.

Some Customers May Not Be Happy With This Change

While the Reusable Cup Benefit is nothing but positive on the surface, at least one media outlet is saying the move could mean serious changes for those who had previously come up with creative ways to bank more stars.

According to TheStreet.com, some Starbucks locations would previously grant 25 stars or 10 cents off an order anytime a customer brought in a reusable cup for their drink. The math doesn’t necessarily work out the same way with the new benefit tied to reusable cups.

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“To make up for the previous number of stars earned, members would have to spend at least $12.50 per order, making it impossible to obtain 25 stars if only ordering a single beverage,” TheStreet.com said in its report.

It is important to note that Starbucks made no mention of the previous benefit when announcing its updated terms of service. Instead, the company is focusing on the message of cutting down on waste and being more eco-friendly.