Couriers are distinguished from ordinary mail services by features such as speed, security, tracking, signature, specialization and individualization of express services, and swift delivery times, which are optional for most everyday mail services. As a premium service, couriers are usually more expensive than standard mail services, and their use is normally limited to packages where one or more of these features are considered important enough to warrant the cost. Courier services operate on all scales, from within specific towns or cities, to regional, national and global services.
In ancient history, messages were hand-delivered using a variety of methods, including runners, homing pigeons and riders on horseback. Before the introduction of mechanized courier services, foot messengers physically ran miles to their destinations. Xenophon attributed the first use of couriers to the Persian prince Cyrus the Younger. Famously, the Ancient Greek courier Pheidippides is said to have run 26 miles from Marathon to Athens to bring the news of the Greek victory over the Persians in 490 BCE. The long-distance race known as a marathon is named for this run.
Starting at the time of Augustus, the ancient Greeks and Romans made use of a class of horse and chariot-mounted couriers called anabasii to quickly bring messages and commands long distances. The word anabasii comes from the Greek αναβασις (adscensus, "mounting"). They were contemporary with the Greek hemeredromi, who carried their messages by foot. In Roman Britain, Rufinus made use of anabasii.
In the Middle Ages, royal courts maintained their own messengers who were paid little more than common labourers.
In cities, there are often bicycle couriers or motorcycle couriers but for consignments requiring delivery over greater distance networks, this may often include lorries, railways and aircraft. Many companies who operate under a Just-In-Time or "JIT" inventory method often use on-board couriers (OBCs). On-board couriers are individuals who can travel at a moment's notice anywhere in the world, usually via commercial airlines. While this type of service is the second costliest—general aviation charters are far more expensive—companies analyze the cost of service to engage an on-board courier versus the "cost" the company will realise should the product not arrive by a specified time (an assembly line stopping, untimely court filing, lost sales from product or components missing a delivery deadline, organ transplants).
The genus of the UK sameday courier market stems from the London Taxi companies but soon expanded into dedicated motorcycle despatch riders with the taxi companies setting up separate arms to their companies to cover the courier work. During the late 1970s small provincial and regional companies were popping up throughout the country. Today, there are many large companies offering next-day courier services, including DX Group, UKMail and UK divisions of worldwide couriers such as FedEx, DHL, UPS and TNT City Sprint.
There are many 'specialist' couriers usually for the transportation of items such as freight/palettes, sensitive documents and liquids.
The 'Man & Van'/Freelance courier business model, is highly popular in the United Kingdom, with thousands upon thousands of independent couriers and localised companies, offering next-day and same day services. This is likely to be so popular because of the low business requirements (a vehicle) and the lucrative number of items sent within the UK every day. However, since the dawn of the electronic age the way in which businesses use couriers has changed dramatically. Prior to email and the ability to create PDFs, documents represented a significant proportion of the business. However, over the past 5 years documentation revenues have decreased by 50 percent. In addition customers are also demanding more from their courier partners. Therefore, a shift where, more and more, organisations prefer to use the services of larger organisations who are able to provide more flexibility and levels of service is being witnessed which has led to another level of courier company, the regional couriers. This is usually one of the local companies who have expanded to more than one office to cover an area.
Royal Mail was up until recently a reasonable competitor of most of the large couriers; offering next day and special delivery services. This has however changed, with higher costs, strike action and a lowering public perception of the company. With companies like Royal Mail, it can be difficult to draw a clear-cut line between postal services and couriers.
Some UK couriers offer next-day services to other European countries. FedEx offers next-day air delivery to many EU countries. Cheaper 'By-Road' options are also available, varying from 2 days delivery time (such as France), to up to a week (former USSR countries).
Large couriers often require an account to be held (and this can include daily scheduled collections). Senders are therefore primarily in the commercial/industrial sector (and not the general public); some couriers such as DHL do however allow public sending (at higher cost than regular senders).
In recent years, the increased popularity of Black Friday in the UK has placed some firms under operational stress.