The pilot project, which began in September 2013, allows customers to buy stamps by requesting a code on their mobile phone or through the Swiss Post smartphone app that should be written on the envelope instead of a regular stamp.
In a statement Swiss Post said the product had “attracted a great deal of interest” during its pilot year, with more than 100,000 letters franked using SMS, and as a result it is making the product available permanently.
Swiss Post is collaborating with all major mobile phone companies to provide the service, which is available for A class standard letters weighing up to 100 grams and two centimetres thick.
Under the scheme, customers needing a stamp can text the keyword ‘STAMP’ to 414. They then receive a code which should be written on the top right hand corner of the envelope before being posted.
Codes are for one-time use and are valid for 10 days.
The stamp costs 1.20 francs, including the text message, making it 20 centimes more than a regular stamp.
When the scheme launched some consumer groups objected to the higher price.
“As long as (Swiss) Post maintains a monopoly for mail, sending A class letters should never cost more than one franc,” Michel Rudin, director of the consumers’ forum group told the ATS news agency.
The service was also criticised for its lack of security.
In October a journalist from the Sonntags Blick newspaper managed to send a letter for free by falsifying a code.
However controls have now been put in place to check the validity of all codes, a Swiss Post spokesperson told news agency ATS.
The now permanent service adds to Swiss Post’s increasing range of digital products.
Since 2006 customers have been able to buy stamps online and print them at home using WebStamp.