The mail coach was faster than the stage coach as it only stopped for delivery of mail and generally not for the comfort of the passengers. They were slowly phased out during the 1840s and 1850s, their role being replaced by trains as the railway network expanded.
John Palmer, a theatre owner from Bath, believed that the coach service he had previously run for transporting actors and materials between theatres could be utilised for a countrywide mail delivery service, so in 1782, he suggested to the Post Office in London that they take up the idea. He met resistance from officials who believed that the existing system could not be improved, but eventually the Chancellor of the Exchequer, William Pitt, allowed him to carry out an experimental run between Bristol and London. Under the old system the journey had taken up to 38 hours. The coach, funded by Palmer, left Bristol at 4pm on 2 August 1784 and arrived in London just 16 hours later.
Impressed by the trial run, Pitt authorised the creation of new routes. By the end of 1785 there were services from London to Norwich, Liverpool, Leeds, Dover, Portsmouth, Poole, Exeter, Gloucester, Worcester, Holyhead and Carlisle. A service to Edinburgh was added the next year and Palmer was rewarded by being made Surveyor and Comptroller General of the Post Office.
Initially the coach, horses and driver were all supplied by contractors. There was strong competition for the contracts as they provided a fixed regular income on top of which the companies could charge fares for the passengers. By the beginning of the 19th century the Post Office had their own fleet of coaches with black and scarlet livery. The early coaches were poorly built, but in 1787 the Post Office adopted John Besant's improved and patented design, after which Besant, with his partner John Vidler, enjoyed a monopoly on the supply of coaches, and a virtual monopoly on their upkeep and servicing.
The mail coaches continued unchallenged until the 1830s but the development of railways spelt the end for the service. The first rail delivery between Liverpool and Manchester took place on 11 November 1830. By the early 1840s other rail lines had been constructed and many London-based mail coaches were starting to be withdrawn from service; the final service from London (to Norwich) was shut down in 1846. Regional mail coaches continued into the 1850s, but these too were eventually replaced by rail services.
The mail coaches were originally designed for a driver, seated outside, and up to four passengers inside. The guard (the only Post Office employee on the coach) travelled on the outside at the rear next to the mail box. Later a further passenger was allowed outside, sitting at the front next to the driver, and eventually a second row of seating was added behind him to allow two further passengers to sit outside. Travel could be uncomfortable as the coaches travelled on poor roads and passengers were obliged to dismount from the carriage when going up steep hills to spare the horses (as Charles Dickens describes at the beginning of A Tale of Two Cities). The coaches averaged 7 to 8 mph (11–13 km/h) in summer and about 5 mph (8 km/h) in winter but by the time of Queen Victoria the roads had improved enough to allow speeds of up to 10 mph (16 km/h). Fresh horses were supplied every 10 to 15 miles (16–24 km). Stops to collect mail were short and sometime there would be no stops at all with the guard throwing the mail off the coach and snatching the new deliveries from the postmaster.
The cost of travelling by mail coach was about 1d. a mile more expensive than by private stage coach, but the coach was faster and, in general, less crowded and cleaner. Crowding was a common problem with private stage coaches, which led to them overturning; the limits on numbers of passengers and luggage prevented this occurring on the mail coaches. Travel on the mail coach was nearly always at night; as the roads were less busy the coach could make better speed.
The guard was heavily armed with a blunderbuss and two pistols and dressed in the Post Office livery of scarlet and gold. The mail coaches were thus well defended against highwaymen, and accounts of robberies often confuse them with private stage coaches, though robberies did occur. To prevent corruption and ensure good performance, the guards were paid handsomely and supplied with a generous pension. The mail was their sole charge, meaning that they had to deliver it on foot if a problem arose with the coach and, unlike the driver, they remained with the coach for the whole journey; occasionally guards froze to death from hypothermia in their exposed position outside the coach during the harsh winters (see River Thames frost fairs). The guard was supplied with a timepiece and a posthorn, the former to ensure the schedule was met, the latter to alert the post house to the imminent arrival of the coach and warn tollgate keepers to open the gate (a fine was payable if the coach was forced to stop). Since the coaches had right of way on the roads the horn was also used to advise other road users of their approach.