Certified SMS is a special type of message that includes a PDF document that certifies that the message has been sent, including all communication data (date/time of sending, delivery or error, recipient's number, sender and the content of the message). 

The certificate or document is issued by a recognised entity (a certified local telephone operator). It is therefore valid for any legal or administrative procedure. The certification document is equivalent to a burofax and is valid in Spain, Argentina, Brazil, Chile, Colombia, Peru, Mexico, Dominican Republic, Ecuador, etc. (consult other destinations).

It is necessary to activate this service in the account Preferences, this activation is free of charge. Once the service has been activated, you will be able to send Certified SMS messages from WebSMS and API.

Any sending of Certified SMS requires three additional pieces of information: email where the certificate PDF document will be sent and the name and fiscal identifier of the entity or company sending the message.

Any SMS sent as certified has an additional cost of 11 credits that will be added to the total cost of the sending.

More information on the cost of a Certified SMS can be found at What is the price of an SMS message?