With SMS messaging, carrier filtering is a practice where wireless carriers block the delivery of some or all messages from a specific number because the content or sending patterns of those messages do not comply with the carrier's own policies, or with state, local, or country specific regulations.
Filtering can take place in the United States as well as in the rest of the world, regardless of the origin or destination numbers of a message. Carriers have a legal obligation to follow the policies, laws, and regulations of the country or mobile network where a message is being delivered to.
Additionally carriers proactively seek to prevent SPAM, unsolicited, or questionable messages from reaching their subscribers. This can help prevents loss of business by reducing the likelihood of some subscribers taking actions against carriers, filing complaints, or switching to other carriers.
If your business use SMS messaging you should familiarize yourself with the concepts of carrier filtering. Filtering techniques and practices are kept strictly confidential by carriers and varies significantly from one carrier to the next. While some may have sophisticated algorithms that analyze messages content others may just have a specific set of terms that trigger filtering. Because of the this, Telebroad is not capable of determining precisely why or how certain messages were filtered.
That being said, there are still some tips (see below) that you can follow in order to avoid or minimize the chances of your messages getting filtered.
Is It Possible to Know If Messages Are Being Filtered?
The short answer is no.
As mentioned, due to the variety of filtering systems, Telebroad has a limited ability to verify whether or not your message got filtered by a carrier. Some carriers provide Telebroad with the relevant information while others do not. The matter is further complicated by some carriers reporting filtered messages as delivered to protect analysis of their filtering algorithms.
Filtered messages will simply show up as undelivered. If you start seeing a large volume of undelivered messages you may want to check the validity of some of the phone numbers for those messages and consider changing the messages content or delivery pattern.
What Can you do to Minimize Filtering?
Familiarizing yourself with the rules and regulations of your target market is a good starting point for minimizing the potential of messages filtering.
Even without specific knowledge of a market you can always apply the following tips:
- Always include clear and easy opt-out instructions – this is perhaps the most important tip. If you don't include such instructions or you don't make them clear and easy to follow, recipients may feel their privacy is not respected and are more likely to contact their carrier to handle the situation and block future messages from you.
- Only send messages during daytime hours – unless requested by a recipient, do not send messages too early or too late. Make sure your records and SMS functions take into account the recipient's time zone.
- Create professional messages and clearly identify yourself - to reduce the chances of getting filtered it is in your best interest to create professional and legible messages. Lengthy, exaggerated, and aggressive language should be avoided. Identify your business to remind the recipient who you are and that he gave his consent to receive your message.
- Avoid shortened links – if you must include a website link it is better to have one linking to a relevant page on your site. Do try to keep the link short side but avoid shortened URLs as these disguise your actual address and make increase its potential to get your message marked as SPAM. Try to have only one link in a message if possible.
- Personalize your content and change numbers – large amount of identical messages sent from the same number are more likely to get flagged and blocked by filtering algorithms. Using Telebroad's APIs, try to personalize each message to the recipient by including his name or any other information he provided when he registered. If you are not using code to send messages, at least try to send messages from different numbers.
United States Specifics
Generally speaking U.S. carriers use sophisticated filtering systems that examine content as well as volume and frequency of messages originating from a particular phone number. Content is examined for repetitiveness and possible spam.
Carriers do no accept requests to remove filtering, however most will remove a blocked number from their filtering list after it has stopped sending flagged message for a while. You will need to change the content or the sending patterns of your legitimate messages if they have been blocked.