From the Information Commissioner’s Office website:
What does the law say?
The Privacy and Electronic Communications Regulations 2003 cover the way organisations send direct marketing by electronic means, including by text message (SMS).
Organisations cannot send you marketing text messages you didn’t agree to receive, unless:
- the sender has obtained your details through a sale or negotiations for a sale;
- the messages are about similar products or services offered by the sender; and
- you were given an opportunity to refuse the texts when your details were collected and, if you did not refuse, you were given a simple way to opt out in all the text messages you received.
(The Regulations do not cover marketing text messages sent to business numbers.)
In other words, do not send text messages to any number other than those which you have legitimately been given by your customer during your previous dealings with them, or that they have opted-in with by invitation by you to receive SMS. Good methods for building your database is to include opt-in keywords on a non-premium short code i.e. “Text ALERTS to 84101 for regular updates” on all your marketing material, signage etc.
Never buy lists, download numbers from the internet or use databases that you may have been given in the past to send marketing SMS to.
Now you have your legitimate contact database and are happy that the recipients are happy to hear from you by SMS, you have to given them an opportunity to opt-out from receiving further SMS. The best method of doing this is by using a keyword on a non-premium short code i.e. append your SMS with “to stop SMS send ALERTSTOP to 84101”.
As soon as you receive a request to stop sending SMS messages from any number you must remove them from your database. It is however good policy and manors to reply immediately acknowledging this request and confirm their number has been removed.
This article is only a guideline and is specifically aimed at the United Kingdom, for other countries you should consult the appropriate governing body.