The Royal Mail today launched a new service that allows Mac and Windows users to buy and print their postage stamps online for the first time.

Customers pay for postage online 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 posting in the normal way.

There is no subscription fee to the service, which costs the same as normal postage. All postal options are available, including First Class and international postage.

It's also possible to print a variety of forms online, including a Certificate of Posting and Customs forms for international postings.

Royal Mail's Marketing Director Alex Batchelor said: "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, direct onto an envelope or a label.

"The service is perfect for busy people, but it is also aimed at home workers who post small quantities of mail on a regular basis as well as people who sell goods via auction websites," he added.