Starbucks will require visitors to its coffee shops to purchase something to stay there or use the restrooms, the company announced Monday in a letter to store managers.

The new policy, outlined in a code of conduct, will come into force later this month and will apply to the company’s cafes, terraces and bathrooms.

“Implementing a coffeehouse code of conduct is something most retailers already have in place and is a practical step that will help us prioritize our paying customers who want to sit and enjoy or use the toilet during their visit to our cafes “We need to,” Jaci Anderson, a Starbucks spokeswoman, said in an emailed statement.

Ms. Anderson said that by setting out expectations for customers, the company can “create a better environment for everyone.”

The code of conduct is posted in every store and prohibits behavior such as discrimination, harassment, smoking and begging.

People who violate the rules will be asked to leave the store and employees may call law enforcement, the policy states.

Before implementation of the new policy begins on January 27, store managers will be given 40 hours to prepare stores and employees, according to the company. There will also be training for staff.

This training time will also be used to prepare for other new practices, including asking customers if they want to keep their drink or take it with them and offering unlimited free refills of hot coffee or iced coffee to customers who order a drink to stay.

The changes are part of an attempt by the company to prioritize customers and make stores more inviting, Sara Trilling, president of Starbucks North America, said in a letter to store managers.

“We know from customers that access to comfortable seating and a clean, safe environment is critical to the Starbucks experience they love,” she wrote. “We have also heard from you, our partners, that expectations around how our spaces should be used and who uses them need to be readjusted.”

The changes come as the company responds to declining sales, falling stock prices and grumblings from activist investors. In August, the company named a new CEO, Brian Niccol.

Mr. Niccol outlined the changes the company needed to make in a video in October. “We will simplify our overly complex menu, adjust our pricing architecture and ensure that every customer feels like Starbucks is worth it, every single visit,” he said.

The new purchase requirement overturns a policy introduced by Starbucks in 2018 that said people could use the cafes and restrooms even if they hadn’t purchased anything.

The previous policy was implemented a month after two black men were arrested at a Philadelphia Starbucks while they waited to meet another man for a business meeting.

Officials said the men asked to use the restroom, but an employee denied the request because they hadn’t purchased anything. An employee then called the police and part of the ensuing encounter was captured on video and viewed by millions of people online, leading to boycotts and protests.

In 2022, Starbucks’ then-CEO Howard Schultz said that the company was reconsidering its open bathroom policy.