Royal Mail on Tuesday launched a new service allowing customers to buy and print their postage online, marking the latest innovation to a stamp based postal service which harks back to 1840 and the Penny Black.

Customers will be able to pay for their postage by selecting the appropriate amount for their letter or parcel, and paying by debit or credit card or via a pre pay account.

A unique barcode is then printed directly onto envelopes, labels or paper before the item is posted.

We have launched this service in response to demands from the general public, who want to be able to buy and print their postage online, said the Royal Mail's Marketing Director Alex Batchelor.

Online postage gives customers more choice and flexibility in the way they pay to send their mail.

Royal Mail lost its monopoly on postal deliveries on January 1 and the state owned operator is fighting hard against private competition for business as the industry faces some of the biggest changes in its 350 year history.

The Internet stamps available from cost the same as normal postage.

Consumers can choose from a full range of postal options, from first class to international services, and can also print out a variety of forms online, such as a certificate of posting or customs form.