Royal Mail is taking on online giant Amazon with a trial Sunday parcel delivery service for major retailers.
The move aims at tapping into the seven-days-a-week delivery market, with more consumers expecting Sunday deliveries as part of their online shopping.
In the last year, Royal Mail said it has processed unprecedented parcel volumes, delivering 496 million in the third quarter ending December 27.
Royal Mail said construction of its second, and largest, parcel hub is under way in Daventry in Northamptonshire, with the capacity to process more than one million parcels a day.
Chief commercial officer Nick Landon said: "The UK already trusts us to deliver their purchases six days a week both quickly and conveniently.
"Now, for the first time, our posties will be doing the same thing seven days a week.
"The last year has reset so many customer expectations and the desire for even more convenient and even more frequent parcel deliveries has certainly been one of them.
"We always listen to our customers, both senders and recipients, and the ask here was clear: we love what you do Monday to Saturday, so please do the same on a Sunday.
"So that's what we're doing, as quickly as possible, so we can offer it to more and more customers across the course of this year."
The firm last month admitted parts of the UK could still be experiencing a reduction in postal services due to higher volumes of mail during the lockdown.
Last year the pandemic led to the package and parcel firm reducing delivery days to week days for a period.
Saturday deliveries were reinstated after the nationwide lockdown came to an end.
