As a marketer, it can be tempting to take advantage of the direct line SMS marketing offers to reach out to customers. But one wrong move and you’ll accidentally get your well-intended message marked as spam.
What is carrier filtering?
Carrier filtering is the action phone carriers like AT&T, Verizon, and T-Mobile take to block the delivery of some—or all—messages deemed inappropriate or spammy from a specific number or business.
Carrier filters or “SMS spam filters“ range from keywords that prevent text messages from getting through to advanced machine learning filters that protect customers from an invasion of unwanted messages in real-time.
Typically, customer complaints activate these filters, with the carrier immediately blocking future messages sent from the reported number. But there are a few other reasons for filtering, such as:
To ensure SMS marketing compliance with carrier policies, as well as state, local, or country-specific regulation
To enforce SMS marketing rules and regulations and protect mobile subscribers from unsolicited or unwanted messaging that are abusive or fraudulent—or contains questionable content
To lower mobile subscriber churn and reduce the potential for dissatisfied customers to take legal action and seek damages
Can I know what exactly they filter?
Unfortunately, the answer is no. Carriers don't open about their message filtering systems to prevent spammers from learning how to dodge these protections. Unlike email, where the recipient can choose to allow email addresses, mobile carriers don’t take user preferences into account when blocking a message. So you have to be extra careful when sending text messages to customers.
High chance of the message getting filtered when:
Sending without a URL shortener, as carriers often view third-party shorteners (e.g., bit.ly) as suspicious
*Businesses should pay for their own URL shortener and not use free ones*Using different content in the message body (Split Test) so not the same message is going out to all contacts
Sending long messages
Sending multiple identical messages
Using all CAPS in the message
Links placed at the end of the message
Texting anyone who has not opted into SMS
Best Practices for not getting filtered:
Send a message to 100 or fewer contacts per day
Use a variety of messaging
Try to get a high response rate
*Carriers tend to care more about the response rate. Try to get as many responses from your lead (ex. Reply "No" if you are not interested.)*Always provide a way for subscribers to opt out; carriers heavily filter messages that don’t include STOP language
Do not send SMS messages early in the morning or late at night, as a text message from a business during off-hours may be seen as intrusive
Use a personal tone to sound more human
For each messaging campaign, send a reminder at least one time every 30 days that the consumer has the choice to opt-out and how they can do so.
The initial message (or every 5th message) that you send to a consumer needs to include one of the following keywords for long code or toll-free numbers:
Providing personalized and valuable content
Avoiding common spam words and phrases
Complying with applicable law and industry guidelines
Maintaining a reasonable sending frequency
Requiring opt-in and offering opt-out
Try to avoid using keywords that have a high chance of being filtered (Refer to the pdf file below)