The Royal Mail will stop delivering letters on Saturdays during the coronavirus outbreak.
The company said the move was to "ease the burden" on postal workers.
It follows a huge number of staff illnesses during the pandemic.
Starting this weekend, May 2, Royal Mail will only deliver letters to people's homes on Monday to Friday instead of six days a week.
But bosses stressed that Post Offices will remain open and people will be able to send letters and packages as normal on Saturdays.
Parcels, including Special Delivery and Track, as well as non-account services, will continue to operate six days per week.
Royal Mail will also continue to collect all mail from businesses, post offices and post boxes, it said.
The move comes in response to "significantly high" staff absence rates which the company said could no longer support normal delivery services.
A statement on the website reads: "We continue to work hard to collect, process and deliver the UK’s mail in unprecedented times.
"However, along with other organisations, we are experiencing increased levels of employee absence due to illness and self-isolation.
"Absence rates are currently significantly higher than what we normally expect at this time of year.
"To manage these severe absence levels, we are implementing a range of mitigations.
"These include changing the time guarantee on Special Delivery, deploying non-operational managers in delivery and temporarily no longer delivering letters on a Saturday."
