In England there exists no official selling Sundays as for example in Germany where the hours of trading on Sundays are strictly prescribed by law. This is caused by the missing of a law governing the hours of trading as upon mentioned. Nevertheless the opening times of official institutions as bank institutes and post offices are ruled.
On Sundays the huge department stores are closed usually, but you always can find many corner shops especially in lively areas. These corner shops open from 12pm to 6pm in average. Supermarkets are allowed to open all the week until 10pm as mentioned at the beginning.
During the advent seasons shops in lively shopping areas open until 10pm usually. On Christmas Day, 25th of December, all shops are closed. There are only few exceptional cases.
The bank holidays as Good Friday, Easter Monday, Spring, August, Christmas Day and New Year are lawfully. The bank institutes and post offices have to be closed on bank holidays as well as on Sundays. Indeed you can use the ATMs provided at mostly every bank institute during that time. To buy stamps you should look after a shop signing out “stamps sold here”.
Health Centres and doctors are not allowed to open their surgeries on Sundays and Bank Holidays. Alternatively hospitals are available, of course.
The closing time for Pubs on Sundays and Bank Holidays is at 10.30pm usually.