Per tradition, the Royal Mail plans to cease all deliveries over the spring and Platinum Jubilee bank holidays on June 2 and 3.
Britons living in England, Wales, Scotland and Northern Ireland cannot receive or collect mail over those two days and will have to wait until Saturday, June 3.
But the Royal Mail site advised people to check with their local branch for precise opening times.
Branches offer more than post-related services, and people may find they need to visit a location for a range of other reasons.