The first 250 lockers, for use by its customers, will be in place in early 2025.
Royal Mail said the lockers will provide 24/7 access in convenient locations, offering a parcel sending and collection service.
Jack Clarkson, of Royal Mail, said: “With continued growth in online shopping, we are expanding our range of services for customers to make sending and receiving parcels more convenient than ever.
“Parcel Lockers are just one of the ways that we will achieve this, and with their growth in popularity, it is important that we have our own lockers to offer a modern, quick and convenient option for our customers.”