Certified mail

Registered mail is a mail service offered by postal services in many countries, which allows the sender proof of mailing via a mailing receipt and, upon request, electronic verification that an article was delivered or that a delivery attempt was made. Depending on the country, additional services may also be available, such as:

The name of this service varies from country to country, and postal services in some countries offer more than one level of service under different names (e.g., "certified mail" and "registered mail" in the U.S.). See the country-specific information below for details.

Traditionally, registered mail was a manual process which gave rise to a great variety of distinctive postal markings, like handstamps, and usage of registration labels. Many countries have issued special postal stationery and postage stamps for registered mail. Earlier similar services were known as Money Letters. Today, however, the registration process is largely computerized with barcode registration labels replacing the traditional analog labels having only a printed serial number.

Generally, the item is pre-paid with the normal postage rate and an additional charge known as a registration fee. Upon payment of this fee the sender is given a receipt, and (usually) a unique numbered registration label is affixed to the letter. As the letter travels from post office to post office and through any sorting office, it has to be signed for on a ledger. This process is completed when the letter is delivered and the receiver signs for the item. With computerization and barcode technology, much of the logging once done manually has become simpler and leads to greater options for the sender and receiver alike to access the status of their shipment via the internet. Many postal authorities provide tracing information for registered items on their website.

Internationally, the use of registered mail requires labels with a 13-digit reference number and corresponding barcode. The first two letters indicate registration (usually "RR") while the last 2 letters usually represent the country where the registered item was posted. E.g., RR913282511SG indicating Singapore, RB5584847749CN indicating China or RR123456785KR indicating Korea.

In the turbulent political and religious climate during the reign of Mary Tudor is found the earliest reference to a registration system in the Kingdom of England in London in July 1556 whereby: that the poste between this and the Northe should eche of them keepe a booke and entrye of every letter that he shall receive, the tyme of the deliverie thereof unto his hands with the parties names that shall bring it unto him, whose handes he shall also take to his booke, witnessing the same note to be trewe. This was likely for state security rather than mail security. In 1603, another Order of Council was made whereby all letters had to be recorded. This system was in effect a registration system although it applied to all items sent via the post.

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Wikipedia