Halfpenny post was a term once commonly used in the UK to refer to a cheap postal service that cost just half a penny to send a letter. Today, this term is no longer in use, but there are several synonyms for halfpenny post that you may hear instead. These include penny post, reduced rate postage, economical mail, and low-cost postal service. All of these terms refer to affordable postal options that enable people to send letters and packages without breaking the bank. While the cost of postage has increased significantly since the days of halfpenny post, there are still plenty of options available for those looking to save on postage.