Aldi is the latest supermarket to make the wearing of face coverings mandatory in its UK stores.
The grocery provider has said all customers will be required to wear a face covering unless medically exempt.
The move comes after other supermarket giants, including Morrisons, Tesco and Asda, have made similar moves in the past day.
Aldi has said for a limited time customers who forget to bring a mask will be provided with one, free of charge.
Those who are not medically exempt and refuse to wear a mask will not be permitted entrance to the store.
Giles Hurley, chief executive of Aldi, said: “The safety of our colleagues and customers is our number one priority.
“Wearing a mask is mandatory for everyone that shops at Aldi, except for the small number of people who have a medical exemption.”
Aldi claims it was the first supermarket to introduce electronic traffic light systems across all its stores in order to manage customer numbers.
The supermarket chain has said it continues to operate a number of strict safety measures to protect staff and customers, including the use of screens at checkouts and doubling the number of sanitisation stations in stores.
Aldi latest supermarket to make face coverings mandatory