Starbucks is to test a 5p paper cup charge across all 950 UK stores following a three-month trial in London.

The business said the charge was designed to encourage customers to bring in a reusable cup. The London trials showed a 126% uplift in the use of such cups, measured by the number redeeming a 25p discount given to Starbucks customers for using a reusable cup.

During the 35-store trial, Starbucks worked with environmental charity and behavioural change experts Hubbub, who evaluated the impact of the charge on customer behaviour.

The report showed the percentage of customers bringing their own cup rose from 2.2% before the trial to 5.8% during the trial. The highest volume of customers using reusable cups was in the morning, with 8% of all hot drinks served in reusable mugs or tumblers.

“We saw encouraging results from the first three months of this trial with Hubbub, and what stood out to us was the positive response we had from our employees and customers, who continue to push us to innovate and find ways to reduce waste,” said Starbucks Europe, Middle East and Africa president Martin Brok.

“We’re hoping this charge will remind customers to rethink their use of single-use plastic as it has with plastic bags.”

The funds raised from the 5p cup charge will support recycling and sustainability work with Hubbub.

Starbucks has previously announced plans to axe single-use plastic straws globally by 2020, making a new Starbucks strawless lid standard on iced coffee, tea and espressos (pictured below). The business is also introducing straws made from alternative-materials, including paper or PLA compostable plastic, for frappuccino-blended beverages or customers who prefer or need a straw.