Coffee drinkers who bring reusable cups to cafes are going on social media to report their efforts are wasted.
People across the UK say that some baristas are using paper cups to make their drink before pouring them into a travel mug.
Eco-conscious coffee fans say that bringing the travel mug becomes pointless if it doesn’t save a paper cup from being used.
But UK coffee chains have said it’s not their policy to waste a cup when a customer brings their own.
Incidents have been raised on Twitter in lots of popular UK shops, including Starbucks, Caffe Nero and Pret.
Some customers even say they end up with wasted paper cups when they stay in the cafe.
According to parliamentary papers, there are four times as many coffee shops in the UK now than there were in 2000 and 20% of people visit a coffee shop every day.
About 2.5 billion coffee cups are used and thrown away every year, enough to stretch around the world roughly five and a half times.
A Caffe Nero spokesman told Sky News: “Our policy is we don’t use a paper cup to make drinks for customers who have brought in a reusable cup.
“We have specific communication to our stores around this, which we regularly re-communicate, and we include it in our team training.”
The Caffe Nero spokesman added: “All our cups can be recycled, and we are also supporting the Valpak scheme which helps fund waste service providers to segregate paper cups and get them to the right recycling plants to recycle the cups.”
A Pret spokesman said: “We’re making progress to substantially reduce our coffee cup waste. We doubled our discount for customers who bring in their own reusable cup to 50p in January 2018, and since then, usage has increased almost 20-fold.
“We provide clear training and instructions to all our baristas that paper cups should not be used to make drinks when customers have provided a reusable one.”
Starbucks and Costa did not return a comment when contacted by Sky News.
(c) Sky News 2019: Coffee drinkers claim reusable cup schemes are not cutting paper waste