A Watford delivery office will be one of many Royal Mail depots that will be open on Sundays.
The Caxton Way office will be open between noon and 4pm from Sunday in an initiative designed to make it easier for online shoppers not at home during weekdays to collect their parcels.
Royal Mail’s network of about 1,400 delivery offices is currently open six days a week.
This new scheme will extend the opening hours of about 100 delivery offices with the highest parcels volumes across England, Scotland, Wales and Northern Ireland to seven days a week.
Tony Fox, operations director, said: "We are continuing to be more customer responsive and provide more options for people to receive items they have ordered online.
"I am delighted to pilot Sunday afternoon opening at around 100 of our delivery offices across the UK with the highest parcel volumes, including Watford."